Kuis Tekanan Zat Kelas 8
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- 1.
Faktor-faktor yang memengaruhi besarnya tekanan adalah ….
- A.
A. gaya tekan dan massa benda
- B.
B. gaya tekan dan gaya gravitasi
- C.
C. luas bidang tekan dan gaya tekan
- D.
D. luas bidang tekan dan gaya gravitasi
Correct Answer
C. C. luas bidang tekan dan gaya tekanExplanation
The correct answer is C. luas bidang tekan dan gaya tekan. This is because the pressure exerted by an object is determined by both the force applied and the area over which the force is distributed. The larger the area, the less pressure is exerted, while the greater the force, the more pressure is exerted. Therefore, both the size of the area and the force applied contribute to the magnitude of the pressure.Rate this question:
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- 2.
Sebuah alat pengangkat mobil memiliki luas penampang pengisap kecil A1 sebesar 20 cm2 dan pengisap besar A2 sebesar 50 cm2. Gaya yang harus diberikan untuk mengangkat mobil 20.000 N adalah … N.
- A.
A. 2.000
- B.
B. 4.000
- C.
C. 5.000
- D.
D. 8.000
Correct Answer
D. D. 8.000Explanation
The force required to lift the car can be calculated using the formula F = P x A, where F is the force, P is the pressure, and A is the area. The pressure can be calculated by dividing the force by the area. In this case, the force is 20,000 N, and the area of the larger suction cup is 50 cm2. Therefore, the pressure is 20,000 N / 50 cm2 = 400 N/cm2. To find the force required for the smaller suction cup, we can use the same pressure, but with the area of the smaller suction cup, which is 20 cm2. So the force required for the smaller suction cup is 400 N/cm2 x 20 cm2 = 8,000 N. Therefore, the correct answer is D. 8,000.Rate this question:
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- 3.
Upaya yang dapat dilakukan untuk mendapatkan tekanan yang besar adalah ….
- A.
A. mengurangi gaya tekan dan memperbesar luas bidang
- B.
B. mengurangi gaya tekan dan memperkecil luas bidang
- C.
C. meningkatkan gaya tekan dan memperbesar luas bidang
- D.
D. meningkatkan gaya tekan dan memperkecil luas bidang
Correct Answer
D. D. meningkatkan gaya tekan dan memperkecil luas bidangExplanation
To obtain a greater pressure, one can increase the force applied and decrease the area over which the force is distributed. This is because pressure is defined as force divided by area. By increasing the force and decreasing the area, the resulting pressure will be larger. Therefore, the correct answer is D. meningkatkan gaya tekan dan memperkecil luas bidang.Rate this question:
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- 4.
Seorang penyelam menyelam dengan kedalaman 3 m, massa jenis air 1.000 kg/m3 , konstanta gravitasi pada tempat tersebut adalah 10 N/kg. Besar tekanan hidrostatisnya adalah … N/m2
- A.
A. 3.000
- B.
B. 30.000
- C.
C. 40.000
- D.
D. 50.000
Correct Answer
B. B. 30.000Explanation
The formula to calculate hydrostatic pressure is P = ρgh, where P is the pressure, ρ is the density of the fluid, g is the acceleration due to gravity, and h is the depth. In this question, the depth is given as 3m, the density of water is 1000 kg/m3, and the acceleration due to gravity is 10 N/kg. Plugging these values into the formula, we get P = (1000 kg/m3)(10 N/kg)(3m) = 30,000 N/m2. Therefore, the correct answer is B. 30,000.Rate this question:
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- 5.
Sebuah drum besi dapat mengapung di dalam air disebabkan oleh ….
- A.
A. massa jenis seluruh drum lebih kecil daripada massa jenis air
- B.
B. massa jenis seluruh drum lebih besar daripada massa jenis air
- C.
C. massa jenis bahan pembuat drum lebih kecil daripada massa jenis air
- D.
D. massa jenis bahan pembuat drum lebih besar daripada massa jenis air
Correct Answer
A. A. massa jenis seluruh drum lebih kecil daripada massa jenis airExplanation
The correct answer is A because an object can float in a fluid if its density is less than the density of the fluid. In this case, the density of the entire drum is less than the density of water, allowing it to float.Rate this question:
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- 6.
Berdasarkan tabel tersebut pernyataan yang benar mengenai hubungan tekanan udara dengan ketinggian adalah ….
- A.
A. ketinggian tempat menghambat tekanan udar
- B.
B. semakin rendah tempat maka tekanan udaranya terhambat
- C.
C. semakin tinggi tempat maka tekanan udaranya semakin besar
- D.
D. semakin tinggi tempat maka tekanan udaranya semakin kecil
Correct Answer
D. D. semakin tinggi tempat maka tekanan udaranya semakin kecilExplanation
According to the table, as the altitude increases, the air pressure decreases. This is because as we go higher in the atmosphere, there are fewer air molecules above us, resulting in lower air pressure. Therefore, the statement "semakin tinggi tempat maka tekanan udaranya semakin kecil" (the higher the altitude, the lower the air pressure) is correct.Rate this question:
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- 7.
Teknologi berikut ini yang tidak menggunakan prinsip Archimedes adalah ….
- A.
A. hidrometer
- B.
B. jembatan ponton
- C.
C. balon udara
- D.
D. dongkrak mobil
Correct Answer
D. D. dongkrak mobilExplanation
The correct answer is D. dongkrak mobil. Dongkrak mobil is a car jack, which is a mechanical device used to lift vehicles off the ground. It does not utilize the principle of Archimedes, which is based on buoyancy and the displacement of fluid. Instead, a car jack relies on mechanical force to lift the car.Rate this question:
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- 8.
Sebuah benda memiliki berat 50 N, ketika ditimbang di dalam air beratnya hanya 45 N, maka gaya ke atas yang menekan benda sebesar… N.
- A.
A. 5
- B.
B. 25
- C.
C. 45
- D.
D. 50
Correct Answer
A. A. 5Explanation
When an object is weighed in water, it experiences an upward buoyant force equal to the weight of the water it displaces. In this case, the object weighs 50 N in air but only 45 N in water. This means that the buoyant force acting on the object is 5 N, which is equal to the difference in weight between air and water. Therefore, the upward force pressing on the object is 5 N.Rate this question:
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- 9.
Pada tumbuhan, air dari akar dapat naik sampai ke daun disebabkan oleh daya kapilaritas batang. Pernyataan yang benar terkait peristiwa tersebut adalah ….
- A.
A. di dalam sel-sel akar terjadi peristiwa osmosis sehingga menyebabkan daya kapilaritas batang meningkat
- B.
B. jaringan xilem memiliki diameter yang sangat kecil sehingga memiliki tekanan yang besar untuk menaikkan air ke daun
- C.
C. jaringan floem memiliki diameter yang sangat kecil sehingga memiliki tekanan yang besar untuk menaikkan air ke daun
- D.
D. air dari dalam tanah dapat naik karena daya isap daun yang rendah sehingga tekanan osmosis dalam sel meningkat
Correct Answer
A. A. di dalam sel-sel akar terjadi peristiwa osmosis sehingga menyebabkan daya kapilaritas batang meningkatExplanation
The correct answer is A because it states that osmosis occurs in the cells of the root, causing an increase in the capillary force of the stem. Osmosis is the movement of water molecules from an area of lower solute concentration to an area of higher solute concentration through a semi-permeable membrane. In this case, water moves from the soil, which has a lower solute concentration, into the root cells, which have a higher solute concentration. This influx of water increases the pressure in the cells, contributing to the capillary force that allows water to move up the stem to the leaves.Rate this question:
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- 10.
Pada saat mengukur tekanan darah dengan tensimeter, berlaku hukum ….
- A.
A. Pascal
- B.
B. Archimedes
- C.
C. Boyle
- D.
D. Newton
Correct Answer
A. A. PascalExplanation
The correct answer is A. Pascal. Pascal's law states that the pressure exerted at any point in an enclosed fluid is transmitted equally in all directions. When measuring blood pressure with a sphygmomanometer (tensimeter), the pressure is applied to the cuff, which compresses the artery. According to Pascal's law, this pressure is transmitted through the fluid (blood) in the artery, allowing the measurement of blood pressure.Rate this question:
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Mar 22, 2023Quiz Edited by
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Jan 04, 2020Quiz Created by
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