Question

Q4.
A ball is gently dropped from a height of 20m. If its velocity increases
uniformly at the rate of 10ms-1. with what velocity will it strike the ground?
After what time will it strike the ground?​

Answer 1

the ball strike the ground with 20 m/s.

Answer 2

Question: A ball is gently dropped from a height of 20m. If its velocity increases uniformly at the rate of 10ms-1. with what velocity will it strike the ground? After what time will it strike the ground?

Solution:

Given in question,

Initial velocity = 0 m/s, height = 20 m, acceleration = 10 m/s^2

Time = ?

v^2 - u^2 = 2as (Third Equation Of Motion)

v^2 - 0^2 = 2*10*20

v^2 = 400

v = 20 m/s

v = u + at (First Equation Of Motion)

20 = 0 + 10t

10t = 20

t = 2 sec