Quiz 2: Hukum Gravitasi Newton

1. Dua planet P dan Q mengorbit matahari. Perbandingan jarak planet P dan planet Q ke matahari adalah 4 : 9. Jika periode planet P mengelilingi matahari adalah 24 hari, maka periode planet Q adalah . . . . .

22 hari

72 hari

81 hari

120 hari

58 hari

The period of a planet's orbit around the sun is directly proportional to the distance of the planet from the sun. In this case, the distance ratio between planet P and planet Q is 4:9. Since the period of planet P is given as 24 days, we can set up a proportion to find the period of planet Q. The ratio of the periods will be the inverse of the ratio of the distances, so it will be 9:4. Solving the proportion, we find that the period of planet Q is 81 days.

Explanation

The period of a planet's orbit around the sun is directly proportional to the distance of the planet from the sun. In this case, the distance ratio between planet P and planet Q is 4:9. Since the period of planet P is given as 24 days, we can set up a proportion to find the period of planet Q. The ratio of the periods will be the inverse of the ratio of the distances, so it will be 9:4. Solving the proportion, we find that the period of planet Q is 81 days.

2. Jika percepatan gravitasi di permukaan bumi adalah g dan percepatan gravitasi pada ketinggian tertentu di atas permukaan bumi adalah g', berapakah percepatan gravitasi pada ketinggian R di atas permukaan bumi ? R adalah jari-jari bumi

1/2 g

1/3 g

1/4 g

2 g

3 g

The acceleration due to gravity at a certain height above the surface of the Earth is denoted as g'. The question asks for the acceleration due to gravity at a height R above the surface of the Earth, where R is the radius of the Earth. Since the acceleration due to gravity decreases with increasing height, the value of g at height R will be less than g'. The correct answer, 1/4 g, indicates that the acceleration due to gravity at height R is one-fourth of the acceleration due to gravity at the given height above the surface of the Earth.

Explanation

The acceleration due to gravity at a certain height above the surface of the Earth is denoted as g'. The question asks for the acceleration due to gravity at a height R above the surface of the Earth, where R is the radius of the Earth. Since the acceleration due to gravity decreases with increasing height, the value of g at height R will be less than g'. The correct answer, 1/4 g, indicates that the acceleration due to gravity at height R is one-fourth of the acceleration due to gravity at the given height above the surface of the Earth.

3. Besar gaya gravitasi antara dua massa yang berjarak tertentu satu sama lain adalah . . . .

Berbanding lurus dengan jarak kedua benda

Berbanding terbalik dengan jarak kedua benda

Berbanding lurus dengan kuadrat jarak kedua benda

Berbanding lurus dengan akar jarak kedua benda

Benbanding terbalik dengan kuadrat jarak kedua benda

The correct answer is "Berbanding terbalik dengan kuadrat jarak kedua benda". This means that the gravitational force between two masses is inversely proportional to the square of the distance between them. In other words, as the distance between the masses increases, the gravitational force decreases, and as the distance decreases, the gravitational force increases. This relationship is described by Newton's law of universal gravitation.

Explanation

The correct answer is "Berbanding terbalik dengan kuadrat jarak kedua benda". This means that the gravitational force between two masses is inversely proportional to the square of the distance between them. In other words, as the distance between the masses increases, the gravitational force decreases, and as the distance decreases, the gravitational force increases. This relationship is described by Newton's law of universal gravitation.

4. Berikut pernyataan-pernyataan mengenai potensial gravitasi.

Besarnya sama dengan energy potensial gravitasi per satuan massa.
Besaran scalar
Besar potensial gravitasi pada suatu titik yang timbul dari dua benda atau lebih sebanding dengan jumlah scalar dari semua potensial gravitasi yang ditimbulkan setiap benda.
Semakin tinggi di atas permukaan bumi, semakin besar potensial gravitasi.

Pernyataan-pernyataan yang tepat adalah nomor . . . . .

1), 2), dan 3)

1), dan 3)

2) dan 4)

4) saja

1), 2), 3), dan 4)

The correct answer is 1), 2), and 3). The first statement states that the magnitude of gravitational potential is equal to the gravitational potential energy per unit mass. The second statement states that gravitational potential is a scalar quantity. The third statement states that the gravitational potential increases with height above the surface of the Earth. Therefore, all three statements are correct.

Explanation

The correct answer is 1), 2), and 3). The first statement states that the magnitude of gravitational potential is equal to the gravitational potential energy per unit mass. The second statement states that gravitational potential is a scalar quantity. The third statement states that the gravitational potential increases with height above the surface of the Earth. Therefore, all three statements are correct.

5. Gaya gravitasi diabaikan dalam tinjauan partikel-partikel elementer karena . . . . .

Gaya gravitasinya sangat lemah

Partikel-partikel elementer tidak ada gaya gravitasinya

Gaya gravitasinya terlalu kuat

Terlalu sulit perhitungannya

Jarak antarpartikel terlalu kecil

The explanation for the given correct answer is that the gravitational force between elementary particles is extremely weak compared to other fundamental forces, such as electromagnetic or nuclear forces. Therefore, when studying the behavior and interactions of elementary particles, the gravitational force can be neglected or ignored without significantly affecting the accuracy of the calculations or predictions.

Explanation

The explanation for the given correct answer is that the gravitational force between elementary particles is extremely weak compared to other fundamental forces, such as electromagnetic or nuclear forces. Therefore, when studying the behavior and interactions of elementary particles, the gravitational force can be neglected or ignored without significantly affecting the accuracy of the calculations or predictions.

6. Planet Uranus memiliki massa 3 kali bumi dan diameternya 4 kali diameter bumi. Apabila percepatan gravitasi bumi 9,8 m/s², maka percepatan gravitasi Uranus adalah . . . . .

2,75 m/s2

7,35 m/s2

5,25 m/s2

1,5 m/s2

4,25 m/s2

The acceleration due to gravity on a planet is determined by its mass and diameter. Since Uranus has a mass 3 times that of Earth and a diameter 4 times that of Earth, its acceleration due to gravity can be calculated using the formula: acceleration = (mass of planet * acceleration due to gravity on Earth) / (diameter of planet)^2. Plugging in the values, we get: (3 * 9.8) / (4^2) = 7.35 m/s^2. Therefore, the correct answer is 7.35 m/s^2.

Explanation

The acceleration due to gravity on a planet is determined by its mass and diameter. Since Uranus has a mass 3 times that of Earth and a diameter 4 times that of Earth, its acceleration due to gravity can be calculated using the formula: acceleration = (mass of planet * acceleration due to gravity on Earth) / (diameter of planet)^2. Plugging in the values, we get: (3 * 9.8) / (4^2) = 7.35 m/s^2. Therefore, the correct answer is 7.35 m/s^2.

7. Percepatan gravitasi di suatu planet sama dengan di permukaan bumi. Jika massa bumi M dan diameter planet 2 kali diameter bumi, maka massa planet sama dengan . . . . .

1/4 M

1/2 M

M

2 M

4 M

The acceleration due to gravity on a planet is determined by its mass and radius. In this question, it is stated that the acceleration due to gravity on the planet is the same as on Earth. Since the diameter of the planet is twice that of Earth, its radius would be twice as well. The acceleration due to gravity is inversely proportional to the square of the radius. Therefore, if the radius is doubled, the acceleration due to gravity would be 1/4 of the value on Earth. The mass of the planet is not given in the question, so it cannot be determined. Therefore, the correct answer cannot be determined.

Explanation

The acceleration due to gravity on a planet is determined by its mass and radius. In this question, it is stated that the acceleration due to gravity on the planet is the same as on Earth. Since the diameter of the planet is twice that of Earth, its radius would be twice as well. The acceleration due to gravity is inversely proportional to the square of the radius. Therefore, if the radius is doubled, the acceleration due to gravity would be 1/4 of the value on Earth. The mass of the planet is not given in the question, so it cannot be determined. Therefore, the correct answer cannot be determined.

8. Suatu benda mengalami percepatan gravitasi 6 m/s² di permukaan sebuah planet. Jika massa planet tersebut adalah 3,6 x 10²¹ kg, berapakah percepatan gravitasi yang akan dialami benda tersebut pada ketinggian 100 km di atas permukaan planet tersebut ?

2 m/s2

2,6 m/s2

3 m/s2

4 m/s2

4,4 m/s2

not-available-via-ai

Explanation

not-available-via-ai

9. Mengenai gerak edar planet, hukum kepler menyatakan bahwa . . . . .

Orbit matahari berupa elips dengan bumi berada pada salah satu titik fokusnya

Perbandingan kuadrat periode revolusi untuk dua planet sama dengan perbandingan kuadrat jarak rata-rata dari matahari

Dalam selang waktu yang sama, garis penghubung matahari – planet menyapu luas yang sama

Gerak planet lebih cepat di aphelium dan lebih lambat di perihelium

Orbit planet ada yang berbentuk elips dan ada juga yang berbentuk lingkaran

The explanation for the given correct answer is that according to Kepler's law, the line connecting the sun and a planet sweeps out equal areas in equal time intervals. This means that as a planet moves around its orbit, it covers equal areas in equal amounts of time. This implies that the planet moves faster when it is closer to the sun (perihelium) and slower when it is farther away (aphelium). This is because the planet needs to cover a larger distance in the same amount of time when it is farther from the sun.

Explanation

The explanation for the given correct answer is that according to Kepler's law, the line connecting the sun and a planet sweeps out equal areas in equal time intervals. This means that as a planet moves around its orbit, it covers equal areas in equal amounts of time. This implies that the planet moves faster when it is closer to the sun (perihelium) and slower when it is farther away (aphelium). This is because the planet needs to cover a larger distance in the same amount of time when it is farther from the sun.

10. Dua buah benda terletak pada satu garis lurus AB yang jaraknya 1 m. Besar massa A dan B masing-masing 72 kg dan 32 kg. Dimanakah benda C yang bermassa 40 kg harus diletakan agar gaya gravitasi pada benda C adalah nol.

0,6 m dari benda A

0,6 m dari benda B

0,4 m dari benda A

0,5 m dari benda A

0,7 m dari benda B

According to the law of gravitation, the gravitational force between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. In this case, the mass of object A is greater than the mass of object B, so the gravitational force between A and C will be stronger than between B and C. To make the gravitational force on object C zero, it should be placed closer to object A. Therefore, object C should be placed 0.6 m from object A.

Explanation

According to the law of gravitation, the gravitational force between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. In this case, the mass of object A is greater than the mass of object B, so the gravitational force between A and C will be stronger than between B and C. To make the gravitational force on object C zero, it should be placed closer to object A. Therefore, object C should be placed 0.6 m from object A.