Question

A ball is thrown straight up in the air. For which situation are both the instantaneous velocity and the acceleration zero? (a) on the way up (b) at the top of its flight path (c) on the way down (d) halfway up and halfway down (e) none of the above

Short answer

The correct option is (e): none of the above.

Step-by-step solution

Define instantaneous velocity and acceleration

The rate of change of position for a very short time frame is characterized as instantaneous velocity (almost zero). The SI unit of speed is m/s.

The rate at which an object's velocity changes with respect to time is called acceleration.

Determining if the value of instantaneous velocity and the acceleration zero

(a)

The ball is a freely falling body with a constant, nonzero acceleration of a=g once it leaves the thrower's hand. The ball's acceleration is not zero on the way up.

Thus, for this situation, both the instantaneous velocity and the acceleration is not zero.

Option (a) is incorrect.

Reasoning if the value of instantaneous velocity and the acceleration zero

(b)

The ball is a freely falling body with a constant, nonzero acceleration of a=g once it leaves the thrower's hand. The ball's acceleration is not zero at the top of its flight path.

Option (b) is incorrect.

Checking if the value of instantaneous velocity and the acceleration zero

(c)

The ball is a freely falling body with a constant, nonzero acceleration of a=g once it leaves the thrower's hand. The ball's acceleration is not zero on the way down.

Option (c) is incorrect.

Seeing if the value of instantaneous velocity and the acceleration are zero

(d)

The ball is a freely falling body with a constant, nonzero acceleration of a=g once it leaves the thrower's hand. The ball's acceleration is not zero halfway up and halfway down.

Option (d) is incorrect.

Therefore, the correct option is (e), none of the above.