Motion in Gravitational Fields Multiple Choice Quiz 7

The gravitational potential energy of an object near Earth’s surface is changed. This could be done by:

A gaseous planet expands and contracts in size while maintaining the same mass. In which diagram is the object at “X” experiencing the greatest gravitational force? (the diagrams are to scale)

What is the gravitational potential energy of an asteroid with a mass of 3.5 x 105 kg when it is at an altitude of 30 km above the ocean? Use: radius of Earth = 6370 km

If the radius of the Earth is 6380 km, what is the gravitational potential energy of a 2.00 kg rock on the surface of the Earth?

If the weight of an astronaut on Earth is 736 N, what is their weight on Mars?

The weight of a 75 kg person decreases to exactly half of its old value when the person moves from the Earth’s surface to a different position. This different position could be:

The gravitational acceleration on a planet is 20 % less than that on the Earth. A rocket takes a man from the Earth to this planet. On neglecting the effect of all other bodies in the sky, which curve in the figure best describes the change in the man’s weight with distance travelled?

The gravitational potential energy of two masses at a distance 2.0 m apart is – 8.0 J.
What external work must be done on this system to separate the masses to a distance of 4.0 m?

The equation Ep=mgh, in which g is 9.8 ms-2, cannot be used for calculating the gravitational potential energy of an orbiting Earth satellite. Which of the following correctly describes the reason for this?

The acceleration due to gravity on the surface of Mercury is 3.6 m s-2. What is the mass of a 2.0 kg brick on Earth and on Mercury?