Question

You throw a tennis ball straight upward. the initial speed is about 12 m/s. part a how long will it take for the ball to reach its maximum height? express your answer to three significant figures and include the appropriate units.

Answer 1

Answer: 1.2 s

It is given that a ball is thrown vertically upwards with initial velocity, u= 12 m/s.

At the maximum height, instantaneous velocity would be, v= 0 m/s

the ball would decelerate due to gravity,
`g=-9.8m/s^(2)`

using equation of motion,

`v-u=gt\\ \Rightarrow t=(v-u)/(g) \\ \Rightarrow t= \frac {0-12 m/s}{9.8 m/s^(2)}=1.2s`

Hence, the time taken by ball to reach its maximum height is 1.2 s when thrown vertically upward with initial velocity of 12 m/s.