Physics

A baseball is thrown straight upward. What is the ball’s acceleration at its highest point?

(A) 0
(B) \frac{1}{2}g, downward
(C) g, downward
(D) \frac{1}{2}g, upward
(E) g, upward
Physics

A rock is dropped off a cliff and strikes the ground with an impact velocity of 30 m/s. How high was the cliff?

(A) 15 m
(B) 20 m
(C) 30 m
(D) 45 m
(E) 60 m
Physics

Which of the following must always be true?

(I) If an object’s acceleration is constant, then it must move in a straight line.
(II) If an object’s acceleration is zero, then its speed must remain constant.
(III) If an object’s speed remains constant, then its acceleration must be zero.

 

(A) I and II only
(B) I and III only
(C) II only
(D) III only
(E) II and III only
Physics

How long would it take a car, starting from rest and accelerating uniformly in a straight line at 5 m/s2, to cover a distance of 200 m ?

(A) 9.0 s
(B) 10.5 s
(C) 12.0 s
(D) 15.5 s
(E) 20.0 s
Physics

An object that’s moving with constant speed travels once around a circular path. True statements about this motion include which of the following?

(I) The displacement is zero.
(II) The average speed is zero.
(III) The acceleration is zero.

 

(A) I only
(B) I and II only
(C) I and III only
(D) III only
(E) II and III only