Gravitational Phenomena

If Earth’s radius were to shrink while its mass remained constant, what would happen to the gravitational acceleration g on its surface?

1. It would decrease.
2. It would increase.
3. It would remain the same.
4. It would become zero.

Answer: (b) It would increase.

Which of the following is true about the gravitational force experienced by an object at the surface of Earth compared to one in deep space?

1. It is stronger in deep space.
2. It is weaker on the surface of Earth.
3. It is stronger on the surface of Earth.
4. It remains the same in both locations.

Answer: (c) It is stronger on the surface of Earth.

An astronaut weighs 600 N on Earth. What would happen to their weight if they stood on Mars, where gravity is about one-third that of Earth?

1. It would be 600 N.
2. It would be around 200 N.
3. It would be around 1800 N.
4. It would not change because mass remains constant.

Answer: (b) It would be around 200 N.

A spacecraft is traveling between Earth and Mars. At which point would the gravitational force on the spacecraft be the least?

1. When it is closer to Earth
2. When it is closer to Mars
3. At the midpoint between Earth and Mars
4. It remains constant throughout the journey

Answer: (c) At the midpoint between Earth and Mars

A satellite of mass 500 kg orbits Earth at a height where the gravitational acceleration is 4.9 m/s². What is the gravitational force acting on the satellite? (Take g on Earth's surface as 9.8 m/s².)

1. 2340 N
2. 4900 N
3. 9800 N
4. 2450 N

Answer: (d) 2450 N

A satellite orbits the Earth in a circular path. If the Earth’s mass were to suddenly double while the satellite remains at the same altitude, what would happen to its orbital speed?

1. It would decrease by half
2. It would remain the same
3. It would increase but less than double
4. It would exactly double

Answer: (c) It would increase but less than double

Two identical balls are dropped simultaneously, one from the top of a mountain and the other from sea level. Assuming no air resistance, which statement is correct?

1. The ball from the mountain will hit the ground with greater speed.
2. The ball from the mountain will take more time to fall but hit with the same speed.
3. The ball from sea level will hit the ground first.
4. Both balls will hit the ground with the same speed and at the same time.

Answer: (b) The ball from the mountain will take more time to fall but hit with the same speed.

Assertion: The gravitational field strength is the same at all points on Earth. Reasoning: Gravitational field strength is affected by the mass of the Earth and is uniform across its surface. Choose the correct option:

1. Both assertion and reasoning are correct, and reasoning is the correct explanation of the assertion.
2. Both assertion and reasoning are correct, but reasoning is not the correct explanation of the assertion.
3. The assertion is correct, but the reasoning is incorrect.
4. The assertion is incorrect, but the reasoning is correct.

Answer: (d) The assertion is incorrect, but the reasoning is correct.

Assertion: A geostationary satellite remains stationary relative to a specific point on Earth’s surface. Reasoning: A geostationary satellite orbits Earth at the same rotational speed as the Earth, keeping its position fixed relative to a point on the surface. Choose the correct option:

1. Both assertion and reasoning are correct, and reasoning is the correct explanation of the assertion.
2. Both assertion and reasoning are correct, but reasoning is not the correct explanation of the assertion.
3. The assertion is correct, but the reasoning is incorrect.
4. The assertion is incorrect, but the reasoning is correct.

Answer: (a) Both assertion and reasoning are correct, and reasoning is the correct explanation of the assertion.

The table below shows the orbital speed and average distance from the Sun of four planets in a hypothetical solar system. Which of the following conclusions can be drawn from the data? Planet Orbital Speed (km/s) Average Distance from Sun (AU) X 35 0.5 Y 25 1 Z 15 5 W 10 10

1. The closer a planet is to the Sun, the faster it moves in its orbit.
2. The planet with the greatest orbital speed has the longest orbital period.
3. The planets move at the same speed, regardless of distance from the Sun.
4. The planet farthest from the Sun has the strongest gravitational pull from the Sun.

Answer: (a) The closer a planet is to the Sun, the faster it moves in its orbit.