Question

A ball is dropped from a height of 30 m .If its velocity increases uniformly at the rate of 10m/s2,the velocity with which they strike the ground is -
​

Answer 1

★$ANSWER$★

Let us assume, the final velocity with which ball will strike the ground be ‘v’ and time it takes to strike the ground be ‘t’.

Given things :-

Initial Velocity of the ball (u) = 0

Distance or height of fall (s) = 20 m

Downward acceleration (a) = 10 m s-2

As we know

2as = v² – u²

v²= 2as + u²

v² = (2 x 10 x 20 ) + 0

v² = 400

Final velocity of ball (v) = 20 ms-1

t = (v – u)/a

Time taken by the ball to strike (t) = (20 – 0)/10

t = 20/10

t = 2 seconds

The final velocity with which ball will strike the ground is (v) = 20 ms-1

The time it takes to strike the ground (t) = 2 seconds