Question

A solid metal ball and a hollow plastic ball of the same external radius are released from rest in a large vacuum chamber. When each has fallen 1m, they both have the same 1.inertia.2.change in potential energy.3.momentum.4.kinetic energy.5.speed

Answer 1

5. Speed

Step-by-step explanation:

Any object in free fall in a vacuum has the same acceleration towards the ground, called acceleration of gravity:

g = 9.8 m/s^2

This means that the speed of an object in free-fall is always given by the equation

v = u +gt (1)

where u is the initial speed and t is the time.

In this case, both balls start from rest (u=0). Since they have same acceleration, they will cover the same distance, 1 m, in the same time t: this means that according to (1), they will also have same speed.

All the other options listed are wrong since they all depend on the mass of the object, and in this case the two objects have different mass.