Question 1

An artificial satellite orbiting around the Earth does not fall down. This is so because the attraction of Earth:

Accepted Answer

An artificial satellite remains in orbit around the Earth without falling due to the Earth's gravitational pull providing the necessary acceleration for its motion. This acceleration is constant in magnitude but changes in direction as the satellite moves in a circular orbit.

Question 2

A girl is swinging on a swing in sitting position. When the girl stands up, the period of swing will:

Accepted Answer

When a girl on a swing changes from a sitting to a standing position, the effective length of the swing decreases. This change in length affects the swing's period, which is calculated using the formula T = 2π√(l/g), where l represents the effective length and g is the acceleration due to gravity. As the effective length decreases when the girl stands up, the period of swing shortens.

Question 3

A solid cube gets completely immersed in water when a 0.2 kg mass is placed on it. If the mass is removed, the cube is 2 cm above the water level. What is the length of each side of the cube?

Accepted Answer

In this physics problem, a solid cube is placed in water and a 0.2 kg mass is placed on top of it, causing the cube to be completely submerged. When the mass is removed, the cube is 2 cm above the water level. We need to find the length of each side of the cube. To do this, we calculate the volume of the 2 cm portion of the cube using the side length x. The volume is 2x². The mass displaced by this portion is 200 grams. Using the formula Mass = Volume × density, we get 200 = 2x² × 1, which simplifies to x² = 100. Therefore, the length of each side of the cube is 10 cm.

Question 4

Assertion (A): The weight of a body decreases with the increase of altitude on earth. Reason (R): The earth is not a perfect sphere.

Accepted Answer

Explanation: The assertion that the weight of a body decreases with altitude on Earth is true, as gravity weakens with distance from the planet's surface. The reason given, that the Earth is not a perfect sphere, is also true. However, the Earth's shape does not directly cause the decrease in weight with altitude. So, both statements are correct, but the reason does not fully explain the assertion.

Question 5

A car is running on a road at a uniform speed of 60 km/h. The net resultant force on the car is:

Accepted Answer

In this scenario, a car is moving at a steady pace of 60 km/h on a road. When a vehicle travels at a constant speed, there is no acceleration (a=0). According to Newton's second law, F=ma. Therefore, if acceleration is zero, the net resultant force acting on the car is also zero.

Physics - Mechanics — UPSC Previous Year Questions

An artificial satellite orbiting around the Earth does not fall down. This is so because the attraction of Earth:

Year-wise Distribution

Sample Questions

Physics - Mechanics — UPSC Previous Year Questions

An artificial satellite orbiting around the Earth does not fall down. This is so because the attraction of Earth:

Year-wise Distribution

Sample Questions