Abby throws a ball straight up and times it. She sees that the ball goes by the top of a flagpole after 0.50 s and reaches the level of the top of the pole after a total elapsed time of 4.1 s. What was the
Speed of the ball at as it passed the top of the flagpole? Neglect air resistance.
A) 29 m/s
B) 16 m/s
C) 18 m/s
D) 6.4 m/s
E) 33 m/s

Question

Quizplus · Accepted Answer

The ball takes 0.50 s to reach the top of the flagpole and 4.1 s to return to the same level, indicating symmetry in its motion. The time to reach the maximum height is half of the total time, so the time to reach the maximum height is 2.05 s. The speed at the top of the flagpole can be calculated using the equation v = u - gt, where u is the initial speed, g is the acceleration due to gravity (9.8 m/s²), and t is the time. Solving for the speed at 0.50 s gives approximately 18 m/s.

Abby Throws a Ball Straight Up and Times It