Question

A tennis ball is thrown straight up into the air with an initial velocity of 6.8 m/s. How long does it take to reach the top of the trajectory?

Answer 1

0.69 s

Step-by-step explanation:

The tennis ball moves upward with constant acceleration of

g = 9.8 m/s^2

in the downward direction. Therefore, the velocity of the ball at time t is given by

v(t) = u - gt

where

u = 6.8 m/s is the initial velocity

g is the acceleration of gravity

t is the time

At the top of the trajectory, the ball has velocity

v = 0

Solving the formula for t, we find the time taken for the ball to reach the top:

`t=(v-u)/(-g)=(0-6.8)/(-9.8)=0.69 s`