If you toss a ball straight upward at 40 m/s with no air resistance,one second before it reaches the top of its path its speed is
A)zero.
B)10 m/s.
C)20 m/s.
D)30 m/s
E)40 m/s.

Question

Quizplus · Accepted Answer

The acceleration due to gravity is approximately 9.8 m/s^2 downward. If you toss a ball upward at 40 m/s, it will decelerate at this rate. One second before reaching the top, its speed would have decreased by 9.8 m/s from whatever speed it had 1 second earlier. At the very top of its path, its speed is 0 m/s (since it momentarily stops before falling back down). Therefore, one second before reaching the top, its speed would be 9.8 m/s, which is approximately 10 m/s when rounded to the nearest ten, making option B the closest answer.

If You Toss a Ball Straight Upward at 40 M/s