Question

a cricket ball is gently dropped from a height of 20m if its velocity increases uniformly @ 10m per second square with what velocity will it strike the ground and after what time​

Answer 1

Answer:

Height from which the ball is dropped (h) = 20 m .

Acceleration due to gravity (g) = 10 m/s² .

By Laws of Motion we know that :

v² = 2 gh

⇒ v² = 2 × 10 m/s² × 20 m

⇒ v² = 400 m²/s²

⇒ v = 20 m/s

The velocity at which it will strike the ground is 20 m/s .

Explanation:

We are given the height from which the ball is dropped and the rate of change of velocity . We know that rate of change of velocity is the same as acceleration .

Hence we use acceleration due to gravity as 10 m/s² and put the value of height in the equation to find out the value of velocity .

Note that here the final velocity is depicted by v .