Question

A parachute is going upward with a velocity 12m/s. It releases a ball when it is at height of 65 m from the ground. How much time the ball will take to reach the ground?(g = 10$m/s^2$)

• A. 5
• B. 6
• C. 7
• D. 8

Answer 1

The correct option is A

5

Here,

u = 12 m/s , s = -65 m , a = -10 $m/s^2$

s = ut + $\frac{{at}^2}{2}$

-65 = 12t - 5$t^2$

5$t^2$ - 12t - 65 = 0

t = 5,-13

Time taken to reach the ground = 5s