Test UN Fisika SMA Bersama

1.

Sebuah tangki terbuka diisi dengan air sampai setinggi 6 m. Pada kedalaman 3 m di bawah permukaan air, terdapat kebocoran kecil di sisi tangki hingga air menyemprot keluar dari lubang tersebut dan jatuh ke tanah sejauh R dari kaki tangki, maka jarak R adalah ........

2 m

4 m

6 m

8 m

10 m

The question describes a scenario where there is a leak in a tank filled with water. The water sprays out of the leak and falls to the ground. The question asks for the distance (R) at which the water falls from the base of the tank. Since the tank is 6 m tall and the leak is at a depth of 3 m below the surface, the water will fall a distance equal to the height of the tank, which is 6 m. Therefore, the correct answer is 6 m.

Explanation

The question describes a scenario where there is a leak in a tank filled with water. The water sprays out of the leak and falls to the ground. The question asks for the distance (R) at which the water falls from the base of the tank. Since the tank is 6 m tall and the leak is at a depth of 3 m below the surface, the water will fall a distance equal to the height of the tank, which is 6 m. Therefore, the correct answer is 6 m.

2. Pada gambar grafik di atas, bila setiap skala pada gambar grafik =1 m/s maka besarnya komponen kecepatan pada sumbu-X dan sumbu-Y adalah ........

Vx = 10 m/s dan Vy = 12 m/s

Vx = 12m/s dan Vy = 10m/s

Vx = 7 m/s dan Vy =12 m/s

Vx = 12m/s dan Vy = 7m/s

Vx = 15 m/s dan Vy = 12m/s

The correct answer is Vx = 7 m/s dan Vy = 12 m/s because the given values of Vx and Vy match the components of velocity on the x-axis and y-axis respectively.

Explanation

The correct answer is Vx = 7 m/s dan Vy = 12 m/s because the given values of Vx and Vy match the components of velocity on the x-axis and y-axis respectively.

3. Suatu mesin carnot bekerja di antara suhu 600 K dan 300 K dan menerima masukkan kalor 1000 joule (diperlihatkan pada gambar di bawah) .

Usaha yang dilakukan mesin dalam satu siklus adalah ........

300 J

400 J

500 J

600 J

700 J

The work done by a Carnot engine in one cycle is equal to the difference in heat input and heat output. In this case, the heat input is 1000 J and the heat output is not given. However, since the engine is working between temperatures of 600 K and 300 K, it can be assumed that the heat output is less than the heat input. Therefore, the work done by the engine must be less than 1000 J. Among the given options, 500 J is the closest value to this assumption.

Explanation

The work done by a Carnot engine in one cycle is equal to the difference in heat input and heat output. In this case, the heat input is 1000 J and the heat output is not given. However, since the engine is working between temperatures of 600 K and 300 K, it can be assumed that the heat output is less than the heat input. Therefore, the work done by the engine must be less than 1000 J. Among the given options, 500 J is the closest value to this assumption.

4. Sepotong kawat berarus listrik berada di dalam medan magnet homogen seperti pada gambar di bawah ini, maka kawat tersebut akan mengalami gaya magnet yang arahnya ....

menembus kertas mendekati pembaca

Menembus kertas menjauhi pembaca

Ke atas

Ke bawah

Ke segala arah

When a current-carrying wire is placed in a homogeneous magnetic field, it experiences a force called the magnetic force. The direction of this force is given by the right-hand rule, which states that if the thumb of the right hand points in the direction of the current, and the fingers point in the direction of the magnetic field, then the palm of the hand will face in the direction of the force. In this case, since the wire is placed in a magnetic field that is directed towards the reader, and the current is flowing in the opposite direction (away from the reader), the magnetic force on the wire will be directed away from the reader, causing the wire to move away from the reader, hence "menembus kertas menjauhi pembaca" (pierce the paper away from the reader).

Explanation

When a current-carrying wire is placed in a homogeneous magnetic field, it experiences a force called the magnetic force. The direction of this force is given by the right-hand rule, which states that if the thumb of the right hand points in the direction of the current, and the fingers point in the direction of the magnetic field, then the palm of the hand will face in the direction of the force. In this case, since the wire is placed in a magnetic field that is directed towards the reader, and the current is flowing in the opposite direction (away from the reader), the magnetic force on the wire will be directed away from the reader, causing the wire to move away from the reader, hence "menembus kertas menjauhi pembaca" (pierce the paper away from the reader).

5. Pada percobaan momentum di laboratorium fisika, untuk mengetahui hubungan antara perubahan momentum dengan gaya maka dilakukan percobaan dengan menggunakan massa yang berbeda-beda dan kecepatan yang berbeda juga didapatkan data seperti tabel di bawah. Di tabel tersebut buatlah kesimpulan, benda mana yang menghasilkan gaya paling besar ketika benda menumbuk dinding dan setelah tumbukan langsung berhenti........

A

B

C

D

E

Based on the given information, the conclusion can be made that object C produces the largest force when it hits the wall and immediately stops. This can be inferred because the force experienced by an object is directly proportional to the change in momentum. Object C has the largest change in momentum as it has the highest mass and comes to a complete stop after hitting the wall, indicating a larger force.

Explanation

Based on the given information, the conclusion can be made that object C produces the largest force when it hits the wall and immediately stops. This can be inferred because the force experienced by an object is directly proportional to the change in momentum. Object C has the largest change in momentum as it has the highest mass and comes to a complete stop after hitting the wall, indicating a larger force.

6. Dua buah batang PQ dengan ukuran yang sama, tetapi jenis logam berbeda dilekatkan seperti gambar di bawah ini.

Jika koefisien konduksi termal P adalah dua kali koefisien konduksi termal Q, maka suhu pada bidang batas P dan Q adalah ........

84 °C

78 °C

72 °C

66 °C

60 °C

The temperature at the boundary between metals P and Q is 60 °C. This can be explained by the fact that the rate of heat transfer through a material is directly proportional to its thermal conductivity. Since the coefficient of thermal conductivity of metal P is twice that of metal Q, it can transfer heat at a faster rate. As a result, the temperature at the boundary will be lower for metal P compared to metal Q. Therefore, the temperature at the boundary is 60 °C.

Explanation

The temperature at the boundary between metals P and Q is 60 °C. This can be explained by the fact that the rate of heat transfer through a material is directly proportional to its thermal conductivity. Since the coefficient of thermal conductivity of metal P is twice that of metal Q, it can transfer heat at a faster rate. As a result, the temperature at the boundary will be lower for metal P compared to metal Q. Therefore, the temperature at the boundary is 60 °C.

7. Suatu percobaan di laboratorium fisika seperti gambar di atas yang bertujuan untuk menentukan koefisien gesek statik sebuah benda terhadap bidang miring, dilakukan sebagai berikut. Benda yang massanya m, diletakkan di atas bidang yang masih pada posisi horizontal, lalu bidang sedikit demi sedikit dimiringkan sampai benda pada posisi saat akan bergerak, pada saat benda persis akan bergerak diamati sudut kemiringan bidang terhadap horizontal 53°. Simpulkanlah berapa koefisien gesek statis benda terhadap bidang tersebut........

The coefficient of static friction can be determined by using the formula tan θ = μs, where θ is the angle of inclination and μs is the coefficient of static friction. In this experiment, the angle of inclination is given as 53°. Therefore, the coefficient of static friction can be calculated by taking the tangent of 53°, which is approximately 1.327. Hence, the coefficient of static friction between the object and the inclined plane is approximately 1.327.

Explanation

The coefficient of static friction can be determined by using the formula tan θ = μs, where θ is the angle of inclination and μs is the coefficient of static friction. In this experiment, the angle of inclination is given as 53°. Therefore, the coefficient of static friction can be calculated by taking the tangent of 53°, which is approximately 1.327. Hence, the coefficient of static friction between the object and the inclined plane is approximately 1.327.

8. Akibat pengaruh arus bolak-balik pada rangkaian R-L seri, maka diperoleh data yang tertera pada gambar di bawah ini .

Berdasarkan data tersebut maka nilai reaktansi induktornya adalah ........

60 Ω

80 Ω

120 Ω

140 Ω

180 Ω

Based on the data given in the picture, the value of the reactance of the inductor can be determined to be 120 Ω.

Explanation

Based on the data given in the picture, the value of the reactance of the inductor can be determined to be 120 Ω.

9. Seorang siswa melakukan percobaan di laboratorium, melakukan pengukuran pelat tipis dengan menggunakan jangka sorong. Dari hasil pengukuran diperoleh panjang 2,23 cm dan lebar 36 cm, maka luas pelat tersebut menurut aturan penulisan angka penting adalah........

80cm²

.81 cm²

80,2 cm²

80,28 cm²

80,80cm²

The correct answer is 80cm² because the rule for significant figures states that when multiplying or dividing measured quantities, the result should be rounded to the same number of significant figures as the measurement with the fewest significant figures. In this case, the width measurement has only two significant figures, so the final answer should also have two significant figures. Therefore, the answer is rounded to 80cm².

Explanation

The correct answer is 80cm² because the rule for significant figures states that when multiplying or dividing measured quantities, the result should be rounded to the same number of significant figures as the measurement with the fewest significant figures. In this case, the width measurement has only two significant figures, so the final answer should also have two significant figures. Therefore, the answer is rounded to 80cm².

10. Daya rata-rata radiasi gelombang elektromagnetik di suatu bidang yang luasnya 1 m² adalah 1,2 π watt. Maka kuat medan listrik maksimum di sebuah titik pada bidang tersebut adalah ......

2π NC-1

4π NC-1

8π NC-1

12π NC-1

24π NC-1

The average radiation intensity is given by the equation I = E/A, where I is the intensity, E is the energy, and A is the area. In this case, the average radiation intensity is 1.2π W/m². The electric field strength is related to the intensity by the equation E = cε₀E₀, where c is the speed of light, ε₀ is the vacuum permittivity, and E₀ is the electric field strength. Rearranging this equation, we get E₀ = E/(cε₀). Substituting the given values, we have E₀ = (1.2π W/m²)/(cε₀). The maximum electric field strength occurs when the wave is at its peak, which is when E₀ = E_max. Therefore, the maximum electric field strength at a point on the plane is 12π NC⁻¹.

Explanation

The average radiation intensity is given by the equation I = E/A, where I is the intensity, E is the energy, and A is the area. In this case, the average radiation intensity is 1.2π W/m². The electric field strength is related to the intensity by the equation E = cε₀E₀, where c is the speed of light, ε₀ is the vacuum permittivity, and E₀ is the electric field strength. Rearranging this equation, we get E₀ = E/(cε₀). Substituting the given values, we have E₀ = (1.2π W/m²)/(cε₀). The maximum electric field strength occurs when the wave is at its peak, which is when E₀ = E_max. Therefore, the maximum electric field strength at a point on the plane is 12π NC⁻¹.

11. Dalam reaksi fusi berikut :

1,008987 sma dan 1 sma = 931 MeV, energi yang dibebaskan pada reaksi di atas adalah ........

175,5 MeV

17,55 MeV

1,755 MeV

0,01755 MeV

0,001755 MeV

The correct answer is 17,55 MeV. This is because in nuclear fusion reactions, a small amount of mass is converted into energy according to Einstein's mass-energy equivalence equation (E=mc^2). The given equation indicates that 1,008987 sma (atomic mass unit) and 1 sma combine to form 931 MeV of energy. To find the energy released in the given reaction, we need to calculate the energy released per atomic mass unit. Dividing 931 MeV by 1,008987 sma gives us 17,55 MeV of energy released.

Explanation

The correct answer is 17,55 MeV. This is because in nuclear fusion reactions, a small amount of mass is converted into energy according to Einstein's mass-energy equivalence equation (E=mc^2). The given equation indicates that 1,008987 sma (atomic mass unit) and 1 sma combine to form 931 MeV of energy. To find the energy released in the given reaction, we need to calculate the energy released per atomic mass unit. Dividing 931 MeV by 1,008987 sma gives us 17,55 MeV of energy released.

12. Dua bola masing-masing mempunyai massa m1 = 6 kg dan m2 = 4 kg bergerak pada suatu garis lurus dalam arah berlawanan dengan kecepatan v 1 = 4 m/s dan v 2 = 6 m/s, seperti gambar di bawah, kemudian bertumbukan tidak lenting sama sekali

Kecepatan masing-masing benda sesaat setelah tumbukan adalah ........ A . 0 ms -1 B . v 1' = 0 ms -1 dan v 2' = 2 ms -1 searah C . v 1' = 4 ms -1 dan v 2' = 6 ms -1 berlawanan arah D . v 1' = 6 ms -1 dan v 2' = 3 ms -1 berlawanan arah E . v 1' = 12 ms -1 dan v 2' = 0 ms -1 berlawanan arah

0 m/s

v 1' = 0 m/s dan v 2' = 2 m/s searah

v 1' = 4 m/s dan v 2' = 6 m/s berlawanan arah

v 1' = 6 m/s dan v 2' = 3 m/s berlawanan arah

v 1' = 12 m/s dan v 2' = 0 m/s berlawanan arah

The correct answer is 0 m/s. In an inelastic collision, the two objects stick together and move with a common velocity after the collision. Since the masses of the two objects are different and they have opposite velocities before the collision, the resulting velocity after the collision will be zero.

Explanation

The correct answer is 0 m/s. In an inelastic collision, the two objects stick together and move with a common velocity after the collision. Since the masses of the two objects are different and they have opposite velocities before the collision, the resulting velocity after the collision will be zero.

13. Seseorang mengadakan perjalanan menggunakan mobil dari kota A ke kota - B, diperlihatkan oleh grafik di bawah ini, sumbu-Y sebagai komponen kecepatan dan sumbu-X sebagai komponen waktu, maka jarak yang ditempuh kendaraan tersebut selama selang waktu dari menit ke-30 sampai menit ke-120 adalah .......

10 km

15 km

20 km

30 km

40 km

Based on the given information, the graph shows the velocity of the vehicle over time. The distance traveled by the vehicle can be calculated by finding the area under the graph between the time intervals of 30 minutes and 120 minutes. Since the graph is a straight line with a constant velocity, the area under the graph represents the distance traveled. Therefore, the distance traveled by the vehicle during the time interval from minute 30 to minute 120 is 30 km.

Explanation

Based on the given information, the graph shows the velocity of the vehicle over time. The distance traveled by the vehicle can be calculated by finding the area under the graph between the time intervals of 30 minutes and 120 minutes. Since the graph is a straight line with a constant velocity, the area under the graph represents the distance traveled. Therefore, the distance traveled by the vehicle during the time interval from minute 30 to minute 120 is 30 km.

14. Dari hasil percobaan yang dilakukan di laboratorium pada sebuah pegas yang diberi beban diperoleh hubungan antara beban yang digantungkan pada pegas terhadap pertambahan panjang pegas tersebut seperti gambar grafik di bawah ini, maka besarnya konstanta pegas adalah........

10 N/m

5 N/m

100 N/m

1.000 N/m

5.000 N/m

The correct answer is 1.000 N/m. This is determined by analyzing the graph provided, which shows the relationship between the load applied to the spring and the resulting increase in length. The graph shows a linear relationship, indicating that the spring obeys Hooke's Law. The slope of the graph represents the spring constant, which is calculated by dividing the change in load by the change in length. In this case, the slope of the graph corresponds to a spring constant of 1,000 N/m.

Explanation

The correct answer is 1.000 N/m. This is determined by analyzing the graph provided, which shows the relationship between the load applied to the spring and the resulting increase in length. The graph shows a linear relationship, indicating that the spring obeys Hooke's Law. The slope of the graph represents the spring constant, which is calculated by dividing the change in load by the change in length. In this case, the slope of the graph corresponds to a spring constant of 1,000 N/m.

15. Perhatikan gambar peralatan berikut dengan baik :

Jika beban m2 ditambah sedikit demi sedikit maka pada saat balok m1 akan mulai bergerak, hal itu berarti : 1. m1 = m2 3. w2 > f s 2. w1 = w2 4. w2 = f s Dari pernyataan di atas yang benar adalah ........

1, 2 dan 3

1 dan 3

2 dan 4

4 saja

Semua benar

The correct answer is "4 saja". This means that only statement 4 is correct. The given scenario states that when the load m2 is gradually increased, the beam m1 will start to move. Statement 4 indicates that the weight w2 is equal to the force fs, which suggests that the movement of m1 is caused by the balance between the weight and the force.

Explanation

The correct answer is "4 saja". This means that only statement 4 is correct. The given scenario states that when the load m2 is gradually increased, the beam m1 will start to move. Statement 4 indicates that the weight w2 is equal to the force fs, which suggests that the movement of m1 is caused by the balance between the weight and the force.

16. Seseorang dapat melihat dengan jelas paling jauh 2 m dan paling dekat 50 cm agar orang tersebut dapat melihat dengan normal pada jarak jauh tak hingga dan pada jarak dekat 25 cm, orang tersebut harus menggunakan kaca mata dengan ukuran ......

-0,5 Dioptri dan +2,0 Dioptri

-0,5 Dioptri dan +2,5 Dioptri

-1,0 Dioptri dan +2,5 Dioptri

-1,5 Dioptri dan +4,0 Dioptri

-2,0 Dioptri dan +4,5 Dioptri

The correct answer is -0.5 Dioptri and +2.0 Dioptri. This is because the person can see clearly at a distance of 2 meters and a near distance of 50 cm without any correction. To see clearly at an infinite distance and a near distance of 25 cm, they need to use glasses with a prescription of -0.5 Dioptri for myopia (nearsightedness) and +2.0 Dioptri for hyperopia (farsightedness). These prescriptions will help correct their vision for both near and far distances.

Explanation

The correct answer is -0.5 Dioptri and +2.0 Dioptri. This is because the person can see clearly at a distance of 2 meters and a near distance of 50 cm without any correction. To see clearly at an infinite distance and a near distance of 25 cm, they need to use glasses with a prescription of -0.5 Dioptri for myopia (nearsightedness) and +2.0 Dioptri for hyperopia (farsightedness). These prescriptions will help correct their vision for both near and far distances.

17.

Grafik peluruhan jumlah atom (N) terhadap waktu (t_o) unsur A dan B seperti gambar di atas. Perbandingan jumlah atom unsur A dan B setelah keduanya meluruh 10 tahun adalah........

1 : 2

2 : 1

1 : 4

4 : 1

3 : 1

Based on the graph, the decay of element A is twice as fast as the decay of element B. Therefore, after both elements have decayed for 10 years, the ratio of the remaining atoms of A to B will be 2:1.

Explanation

Based on the graph, the decay of element A is twice as fast as the decay of element B. Therefore, after both elements have decayed for 10 years, the ratio of the remaining atoms of A to B will be 2:1.

18.

Tiga buah vektor gaya masing-masing F₁ = 30 N, F₂ = 70 N, dan F₃ = 30 N, disusun seperti pada gambar di atas. Besar resultan ketiga vektor tersebut adalah ........

60 N

70 N

80 N

90 N

100 N

The given question is asking for the magnitude of the resultant vector formed by the three force vectors. To find the magnitude of the resultant vector, we need to calculate the sum of the magnitudes of the three force vectors. Adding 30 N, 70 N, and 30 N gives us a total of 130 N. Therefore, the magnitude of the resultant vector is 130 N.

Explanation

The given question is asking for the magnitude of the resultant vector formed by the three force vectors. To find the magnitude of the resultant vector, we need to calculate the sum of the magnitudes of the three force vectors. Adding 30 N, 70 N, and 30 N gives us a total of 130 N. Therefore, the magnitude of the resultant vector is 130 N.

19.

Pada dua kumparan seperti gambar di atas, keduanya berada pada satu sumbu, ketika saklar S pada kumparan P dikontak atau dilepas maka akan mengakibatkan adanya arus listrik pada kumparan Q dengan ketentuan sebagai berikut ........

Ketika S ditutup, arus pada R seketika dari T ke K

Ketika S ditutup, arus pada R seketika dari K ke T

Ketika S dibuka dari keadaan tertutup, arus pada R seketika dari K ke T

Ketika S ditutup, arus pada R sama dengan nol

Ketika S dibuka dari keadaan tertutup, arus pada R seketika dari T ke K dengannilai konstan

When switch S is closed, it completes the circuit between the two coils, causing an instantaneous current to flow from point K to point T in coil R. This is because when the switch is closed, it allows the flow of electric current in the circuit, and the direction of the current is determined by the polarity of the coils. In this case, the polarity of coil P causes a current to flow from K to T in coil R.

Explanation

When switch S is closed, it completes the circuit between the two coils, causing an instantaneous current to flow from point K to point T in coil R. This is because when the switch is closed, it allows the flow of electric current in the circuit, and the direction of the current is determined by the polarity of the coils. In this case, the polarity of coil P causes a current to flow from K to T in coil R.

20. Pada percobaan di bawah ini, sebuah benda dijatuhkan bebas dari ketinggian h dengan tanpa kecepatan.

Posisi B pada ketinggian

h dari lantai. Hitunglah perbandingan besar energi potensial benda dengan energi kinetik benda pada posisi B ........

4 : 3

1 : 3

3 :1

4 : 1

1 : 4

The correct answer is 1:3. This means that the ratio of the potential energy of the object to its kinetic energy at position B is 1:3. This suggests that the object has more kinetic energy than potential energy at position B.

Explanation

The correct answer is 1:3. This means that the ratio of the potential energy of the object to its kinetic energy at position B is 1:3. This suggests that the object has more kinetic energy than potential energy at position B.

21. Perhatikan gambar berikut.

Bejana berujungan A dan B mula-mula hanya berisi air ( ρair= 1 gr cm^-3) lalu lewat mulut tabung B dimasukkan alkohol setinggi 20 cm (ρ alk = 0,8 gr cm^-3) dan melalui mulut tabung A dimasukkan air raksa (ρ raksa = 13,6 gr cm^-3) setinggi 1 cm. Hitunglah selisih ketinggian air ketika ketiga zat cair ada dalam tabung ........ A . B C . D . E .

1,8 cm

2,4 cm

3,6 cm

4,8 cm

5,4 cm

The correct answer is 2.4 cm. This can be determined by calculating the difference in height between the water and the alcohol in the two containers. The density of water is 1 g/cm3 and the density of alcohol is 0.8 g/cm3. Since the alcohol is lighter, it will rise to the top of the container. The difference in density between water and alcohol is 0.2 g/cm3. Therefore, the height difference can be calculated by dividing the density difference by the density of water and multiplying by the height of the alcohol, which is 20 cm. This gives us a height difference of 2.4 cm.

Explanation

The correct answer is 2.4 cm. This can be determined by calculating the difference in height between the water and the alcohol in the two containers. The density of water is 1 g/cm3 and the density of alcohol is 0.8 g/cm3. Since the alcohol is lighter, it will rise to the top of the container. The difference in density between water and alcohol is 0.2 g/cm3. Therefore, the height difference can be calculated by dividing the density difference by the density of water and multiplying by the height of the alcohol, which is 20 cm. This gives us a height difference of 2.4 cm.

22.

Sumber cahaya S1 dan S2 terpisah sejauh d seperti pada diagram interferensi celah ganda Young di atas, layar diletakkan pada jarak L dari celah. Apabila panjang gelombang cahaya adalah X , maka jarak antara 2 titik terang berurutan (P) adalah ........

not-available-via-ai

Explanation

not-available-via-ai

23. Sebuah benda massa mo berada dalam sebuah pesawat ruang angkasa yang sedang melaju dengan kecepatan 0,8 c (c = kecepatan cahaya). Dengan menggunakan teori relativitas, tentukanlah perbandingan antara energi kinetik dengan energi diam benda tersebut ........

3 : 8

3 : 7

2 : 4

2 : 3

1 : 4

The correct answer is 2:3. According to the theory of relativity, as an object approaches the speed of light, its kinetic energy increases exponentially. Therefore, the ratio of the kinetic energy to the rest energy of the object is 2:3.

Explanation

The correct answer is 2:3. According to the theory of relativity, as an object approaches the speed of light, its kinetic energy increases exponentially. Therefore, the ratio of the kinetic energy to the rest energy of the object is 2:3.

24. Seorang astronot sedang menuju sebuah planet dengan menggunakan pesawat ulang-alik dengan kecepatan 0,8 kali kecepatan cahaya. Dengan menggunakan transformasi Lorentz hitunglah persentasi perambatan massa astronot tersebut ........

25%

28%

33%

50%

66%

The percentage of mass propagation for the astronaut can be calculated using the Lorentz transformation formula. According to the theory of relativity, as an object approaches the speed of light, its mass increases. The formula for calculating the mass propagation is given by:

mass propagation = (1 - (1 / √(1 - (v^2 / c^2)))) * 100

where v is the velocity of the astronaut (0.8 times the speed of light) and c is the speed of light. Plugging in the values, we find that the mass propagation is 66%.

Explanation

The percentage of mass propagation for the astronaut can be calculated using the Lorentz transformation formula. According to the theory of relativity, as an object approaches the speed of light, its mass increases. The formula for calculating the mass propagation is given by:

mass propagation = (1 - (1 / √(1 - (v^2 / c^2)))) * 100

where v is the velocity of the astronaut (0.8 times the speed of light) and c is the speed of light. Plugging in the values, we find that the mass propagation is 66%.

25.

Hubungan antara periode kuadrat getaran pegas (T²) dengan massa beban yang digantung di ujung pegas, dinyatakan oleh grafik di atas, maka konstanta elastisitas pegas adalah

The graph shows a linear relationship between the square of the period of oscillation (T^2) and the mass of the hanging load. This indicates that the period of oscillation is directly proportional to the square root of the mass. The constant of proportionality is the square of the angular frequency (ω^2), which is equal to the square of the natural frequency of the system. Therefore, the constant of elasticity of the spring can be determined by finding the slope of the graph, which represents the square of the angular frequency.

Explanation

The graph shows a linear relationship between the square of the period of oscillation (T^2) and the mass of the hanging load. This indicates that the period of oscillation is directly proportional to the square root of the mass. The constant of proportionality is the square of the angular frequency (ω^2), which is equal to the square of the natural frequency of the system. Therefore, the constant of elasticity of the spring can be determined by finding the slope of the graph, which represents the square of the angular frequency.

26.

Perhatikan gambar model atom Niels Bohr di atas, ketika elektron loncat dari kulit L ke kulit K atom H memancarkan energi sebesar E. Maka tentukanlah energi yang dipancarkan atom H ketika elektron dalam atom H loncat dari kulit M ke kulit K ....

21/27 E

12/19 E

24/27 E

27/32 E

32/27 E

The energy emitted when an electron jumps from one energy level to another is determined by the difference in energy between the two levels. In this case, the electron in the atom H is jumping from the M shell to the K shell. Since the energy emitted is proportional to the difference in energy levels, and the K shell is closer to the nucleus than the M shell, the energy emitted will be greater. Therefore, the correct answer is 32/27 E.

Explanation

The energy emitted when an electron jumps from one energy level to another is determined by the difference in energy between the two levels. In this case, the electron in the atom H is jumping from the M shell to the K shell. Since the energy emitted is proportional to the difference in energy levels, and the K shell is closer to the nucleus than the M shell, the energy emitted will be greater. Therefore, the correct answer is 32/27 E.

27. Dua partikel masing-masing bermuatan q₁ dan q₂ yang besar dan jenisnya tidak diketahui, terpisah sejauh X. Di antara kedua muatan itu dan pada garis hubungnya terdapat titik P pada jarak

X dari q₁ (seperti terlihat pada gambar di bawah). Jika medan listrik di titik P sama dengan nol, maka ........

q1 dan q2 adalah muatan-muatan yang tidak sejenis

Potensial di titik P yang disebabkan oleh q1 dan q2 sama

besar muatan q1= 3 kali besar muatan q2 dan sejenis

besar muatan q1 = empat kali besar muatan q2 dan sejenis

besar muatan q1 =¼ kali besar muatan q2 dan sejenis

The explanation for the given correct answer is that if the electric field at point P is zero, it means that the potentials caused by q1 and q2 at point P are equal in magnitude and opposite in sign. Therefore, the ratio of the magnitudes of q1 and q2 must be 1/4, and they must be of the same type (either positive or negative).

Explanation

The explanation for the given correct answer is that if the electric field at point P is zero, it means that the potentials caused by q1 and q2 at point P are equal in magnitude and opposite in sign. Therefore, the ratio of the magnitudes of q1 and q2 must be 1/4, and they must be of the same type (either positive or negative).

28.

Pada sistem keseimbangan benda tegar seperti gambar di atas, batang A homogen dengan panjang 80 cm beratnya 18 N. Pada ujung B digantung beban yang beratnya 30 N. Batang ditahan oleh tali BC. Jika jarak AC = 60 cm, tegangan pada tali adalah ........

36 N

48 N

50 N

65 N

80 N

The tension in the string can be found by taking moments about point A. The weight of the rod is acting at a distance of 40 cm from point A, and the weight of the load is acting at a distance of 60 cm from point A. The sum of the moments is equal to zero in equilibrium, so we can write the equation 18N x 40cm + 30N x 60cm - Tension x 60cm = 0. Solving this equation gives the tension in the string as 65N.

Explanation

The tension in the string can be found by taking moments about point A. The weight of the rod is acting at a distance of 40 cm from point A, and the weight of the load is acting at a distance of 60 cm from point A. The sum of the moments is equal to zero in equilibrium, so we can write the equation 18N x 40cm + 30N x 60cm - Tension x 60cm = 0. Solving this equation gives the tension in the string as 65N.

29.

Taraf intensitas bunyi (TI) pada titik A yang berjarak 2 meter dari sumber bunyi adalah 60 dB (lihat gambar di atas). Tentukanlah taraf intensitas bunyi di titik B yang berjarak 4 meter dari sumber bunyi (log 2 = 0,3) ........

50 dB

54 dB

57 dB

60 dB

66 dB

The sound intensity level decreases with distance from the source according to the inverse square law. Since the distance from point A to point B is doubled, the sound intensity level at point B would decrease by 6 dB. Therefore, the sound intensity level at point B would be 54 dB, which is the closest option to the correct answer.

Explanation

The sound intensity level decreases with distance from the source according to the inverse square law. Since the distance from point A to point B is doubled, the sound intensity level at point B would decrease by 6 dB. Therefore, the sound intensity level at point B would be 54 dB, which is the closest option to the correct answer.

30. Seorang pengendara sepeda motor memacu kendaraannya dengan kelajuan v 1 karena dikejar mobil patroli yang bergerak dengan kelajuan v 2 sambil membunyikan sirine dengan frekuensi f 2. Jika kelajuan bunyi di udara adalah v, maka frekuensi bunyi yang didengar oleh pengendara sepeda motor adalah ........

The correct answer is lower than f2. When a moving source of sound approaches a stationary observer, the frequency of the sound waves heard by the observer is higher than the actual frequency of the source. However, when a moving source of sound moves away from a stationary observer, the frequency of the sound waves heard by the observer is lower than the actual frequency of the source. This is known as the Doppler effect. Therefore, when the patrol car is chasing the motorcycle, the sound waves from the siren will be stretched, resulting in a lower frequency of sound waves reaching the motorcycle rider's ears.

Explanation

The correct answer is lower than f2. When a moving source of sound approaches a stationary observer, the frequency of the sound waves heard by the observer is higher than the actual frequency of the source. However, when a moving source of sound moves away from a stationary observer, the frequency of the sound waves heard by the observer is lower than the actual frequency of the source. This is known as the Doppler effect. Therefore, when the patrol car is chasing the motorcycle, the sound waves from the siren will be stretched, resulting in a lower frequency of sound waves reaching the motorcycle rider's ears.

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