Free Gravitation MCQs with Answers

261. The weight of a pilot diving down with an acceleration of 9.8ms -2 will become:

• A. Double
• B. Half
• C. Zero
• D. Negative

Explanation: When an object is in free fall, such as a pilot diving down with an acceleration equal to gravity (9.8 m/s-2), it experiences weightlessness. This occurs because the only force acting on the object is gravity, and there is no normal force counteracting it. Thus, the weight, which is the normal force exerted by a surface, is effectively zero. The other options are incorrect as they suggest changes to gravity or forces that do not apply in the context of free fall.

262. An object in a satellite orbiting around the Earth is weightless because:

• A. g=0
• B. It is falling freely
• C. No force acts on it
• D. It is far away from the earth

Explanation: No force acts on it: This option is incorrect. There is a force acting on the object due to gravity, but it is balanced by the centripetal force of the satellite's orbital motion.

263. The pilot weighting 686N dived down with an acceleration of 9.8m sec-2 its apparent weight is

• A. 343N
• B. 1372 N
• C. 686 N
• D. Zero

Explanation: The net force is equal to the sum of the gravitational force and the force due to acceleration:Net force = Gravitational force + Force due to accelerationNet force = 686N + (mass × acceleration)Since the gravitational force is equal to the weight, we have:Net force = Weight + (mass × acceleration)Net force = 686N + (mass × 9.8 m/s²)Now, if the pilot is in free fall with no other external forces acting on them, we can consider the net force to be zero because the gravitational force and the force due to acceleration cancel each other out. Therefore, the apparent weight of the pilot in this scenario is zero.

264. The weight of a pilot when diving down in a jet plane with an acceleration of 9.8m/s2 will become

• A. Double
• B. Half
• C. Negative
• D. Zero

Explanation: Weight of pilot = Original Weight + Apparent Weight = mg+(-ma) a= 9.8ms-2 So weight of pilot = 0

265. An object in a satellite orbiting around the earth is weightless because:

• A. g = 0
• B. No force acts on it
• C. Its motion is free fall
• D. It is far away from the earth

Explanation: The correct answer is that an object in a satellite orbiting around the Earth is weightless because its motion is in free fall. In orbit, both the satellite and the objects inside it are in a constant state of free fall towards the Earth, but because they are moving forward fast enough, they keep missing it. This continuous free-fall condition results in the experience of weightlessness. While the force of gravity does act on the objects, the lack of a normal contact force, which we associate with weight, is what makes them feel weightless. This is different from the idea that gravity is zero or that no force acts on the object.