A ball is thrown upwards.Neglecting air resistance,what initial upward speed does the ball need to remain in the air for a total time of 10 seconds?
A)about 50 m/s
B)about 60 m/s
C)about 80 m/s
D)about 100 m/s
E)about 110 m/s

Question

Quizplus · Accepted Answer

The total time in the air is 10 seconds, so the time to reach the peak is 5 seconds. Using the formula $v = u + at$ with $v = 0$ at the peak, $a = -9.8 \, \text{m/s}^2$, and $t = 5 \, \text{s}$, we find $u = 49 \, \text{m/s}$, which is approximately 50 m/s.

A Ball Is Thrown Upwards