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 1 m, they both have the same?

time of fall and the final velocity

Explanation:

the mass of solid ball is more than the mass of hollow ball.

According to the third equation of motion

v² = u² + 2gh

As the final velocity v does not depend on the mass of the object, so the final velocity of both the ball is same.

According to the first equation of motion

v = u + gt

As v is same for both the balls, the time is also same for both the balls.

So, they both have same time of fall and final velocity.