Question

A ball is thrown vertically upward with a speed of $25.0m/s$. What is its velocity when it returns to the level from which it started? (in m/s)

• A. $30$
  
• B. $25$
  
• C. $63$
  
• D. $45$
  

Answer 1

The correct option is B $25$

For upward motion:
Applying $3rd$ eqn of motion,
$v^2=u^2+2aS$
$0=25\times 25-2gH$ where $H$ is maximum height attained
$H=625/2g$
For downward motion:
Applying $3rd$ eqn of motion,
$v^2=u^2+2aS$
$v^2=0\times 0+2g\times 625/2g$ where $H$ is maximum height attained
$v^2=625m/s$
$v=25m/s$