Question

A ball is thrown vertically upward with a speed of $25.0m/s$. How long does it take to reach its highest point?

• A. $1s$
• B. $9s$
  
• C. $2.5s$
  
• D. $2s$
  

Answer 1

The correct option is C $2.5s$

When the ball reaches the highest point, its velocity will be zero. So final velocity is $v=0m/s$.

Consider upward motion, the acceleration of the ball is $a=-g=-9.8m/s^2$ (minus for motion opposite to gravity)

If $t$ be the required time.

Using $v=u+at$,

$0=25+(-9.8)t$

$⟹$ $t=2.5s$