Question

Two balls having different masses reach the same height when shot into the air from
the ground. If there is no air resistance, which of the following statements must be
true? (More than one statement may be true.)
(a) Both balls left the ground with the same speed.
(b) Both balls left the ground with the same kinetic energy.(c) Both balls will have the same gravitational potential energy at the highest point.
(d) The heavier ball must have left the ground with a greater speed than the lighter
ball.
(e) Both balls have no acceleration at their highest point.

Answer 1

I think its d & e

Answer 2

@cormacpayne

Answer 3

@Ashleyisakitty
@campbell_st

Answer 4

At their highest point, there is gravity pulling down on the balls, so there is acceleration, and therefore E is not an answer.

Answer 5

then a & d

Answer 6

Kinematics is independent of mass, and all formulas involving distance, speed, and time only involve displacement, velocity, acceleration, and time, no mass. Therefore, the balls can be shot into the air with the same speed and will travel the same distance, therefore D is not the answer.

Answer 7

so is it only d

Answer 8

i meant a

Answer 9

Correct! B is not an answer because we know they left with the same speed, but kinetic energy also involves mass, so the larger ball will have more kinetic energy. C is not an answer because gravitational potential energy involves mass, so the larger ball will have more potential energy.