MEDAL GIVEN TO CORRECT ANSWER.

A ball is thrown with a speed of 10 m/s at an angle of 65. Which of the following statements describes the motion of the ball at the top of its trajectory?

A. The vertical acceleration is constant.
B. The horizontal component of velocity is zero.
C. The horizontal component of velocity is increasing.
D. The vertical acceleration is zero.

Question

MEDAL GIVEN TO CORRECT ANSWER. 

A ball is thrown with a speed of 10 m/s at an angle of 65. Which of the following statements describes the motion of the ball at the top of its trajectory?

 		A.	The vertical acceleration is constant.
 		B.	The horizontal component of velocity is zero.
 		C.	The horizontal component of velocity is increasing.
 		D.	The vertical acceleration is zero.

anonymous · Answer

A, the vertical acceleration is always gravity (-9.8) and is constant...horizontal velocity does not change, and it is not zero (so B and C are wrong).  D is wrong because the acceleration is -9.8.  Thus A is the correct answer.