Question

You are on the Moon. An iron ball of mass 3 kg is released from a height

of 125 metres and falls freely towards the ground.

If the value of ‘g’ on Earth is 9.6 metres/ sec2

, find -

a. Time taken by the ball to reach the ground

b. Velocity of the ball when it touches the ground

c. Height of the ball at half the time it takes to reach the ground​

Answer 1

Answer:

An iron ball of mass 3 kg is released from a height of 125 m and falls freely to the ground. Assuming that the value of g is 10 m/s, calculate (i) time taken by the ball to reach the ground (ii) velocity of the ball on reaching the ground (iii) the height of the ball at half the time it takes to reach the ground.

Hope it helps ....

Answer 2

Answer:

S=125=UT+1/2AT^2

as U is =0

therefore S=1/2AT^2

here A is 10m/s^2

therefore

125=1/2AT^2

250=10T^2

therefore T =√25=5sec

V^2-U^2=2AS

here A is -10 and S is -125m as its falling from a height and U =0 therefore

V^2=2(-10)(-125)

V=√2500

V=50m/s

half time by it reaches =5/2=2.5sec

S=UT+1/2AT^2

S=1/2x10xT^2

therefore S=31.25m

but H=125-31.25

therefore H=93.75m

a)The time by which the ball reaches the ground is=5seconds

b) The velocity of the ball on reaching the ground=50m/s

c) The height of the ball at half time it takes to reach the ground=93.75m

I hope this will help you