Answer :
Its kinetic energy at that point will be equal to its gravitational potential energy just before the fall, given by E=mgh=0.95*9.8*3.0=27.93J
As per the question the apple is present at a height of 3 m above the ground.
The mass of the apple is given as 0.95 kg.
Now we have to calculate the potential energy of the apple at that height. Potential energy is the energy due to the position or configuration of the the body.
Mathematically potential energy=mass of the body×acceleration due to gravity×height of the body from the ground
i.e P.E=mgh
Where m is the mass, g is the acceleration due to gravity and h is the height.
As per the question m=0.95 kg
h=3 m
And we know g=9.8 m/s^2
hence P.E=mgh
=0.95 kg×9.8 m/s^2×3m
=27.93 J
We have been asked to calculate the kinetic energy of the apple when it just reaches the ground.
Before going to solve this first we have to know that the law of conservation of energy.
It states that energy can't be created nor be destroyed.The total energy of the system is always constant.
Hence the total mechanical energy of the apple at a height of 3 m is equal to the total kinetic energy of the apple when it just reaches the ground.
Here we have neglected air resistance.
The total mechanical energy at height of 3 m is nothing else than the total potential energy of the apple at that height.
Hence K.E=P.E
⇒K.E=27.93 J [ans]