Question

What will the ball's speed be when it returns to its starting point? (in m/s)

• A. $8$
  
• B. $4$
  
• C. $5$
  
• D. $7$
  

Answer 1

The correct option is A $8$

Considering upward direction to be positive direction.
Initial velocity $u=8m/s$
Since the ball returns to the starting point, displacement of the ball is zero i.e. $S=0$
Using $v^2-u^2=2gS$
Or $v^2-8^2=0$
$⟹v=8m/s$ (downwards)