Question

an apple of mass 0.1kg is dropped from a hight of 1m find the value of kinetic energy when it hits the ground​

Answer 1

Answer:

W = mgh = 0.1*10*1m =1 J ( 1 joule of work needed).

Neglecting air resistance, the speed the apple will hot the ground with is independent on its mass.

v = sqrt(2gh) =sqrt(2*10*1) = 4.5 m/s

Power = E/t

t needed to hit the ground is given by:

gt^2/2 = h = 1m

t = sqrt(2h/g) = sqrt(0.2) =0.45 s

So power spent until hitting the ground is 1/.45 = 2.2 W

Note that in 1s the apple would have fallen 5*1^2/2 = 2.5 m more than its original height! (1m).

Answer 2

Given,

Mass = 0.1kg

Gravitational force = 10m/s

Height = 1m

Solution:

Potential Energy = Kinetic Energy

mgh = K.E

0.1 × 10 × 1 = K.E

1 = K.E

So, K.E = 1 j or 1 joule