Author Question: For this problem, assume that the acceleration of gravity is 10 m/s2 downward, and that all friction ... (Read 141 times)

AEWBW · **on:** Jul 27, 2018

For this problem, assume that the acceleration of gravity is 10 m/s2 downward, and that all friction effects can be neglected. A ball is thrown upward at a velocity of 20 m/s. What is its velocity after 3 s?

A) zero
B) 10 m/s upward
C) 10 m/s downward
D) 20 m/s downward
E) 20 m/s upward

Question 2

A toy rocket, weighing 10. N, blasts off from ground level. At the exact top of its trajectory, its energy is 140. J. To what vertical height does it rise?

A) 1.4 m
B) 14. m
C) 12. m
D) 0.12 km
E) 1.4 km