Question

(b) An object of mass 2 kg is raised to a height of 10 m above the ground. It is then
allowed to fall freely. If g= 10 m/s?,calculate-
(i) Its Potential energy at 10 m height.
(ü) Kinetic energy of the body when it is half way through its journey downwards.
(ii) Mention the type of energy conservation taking place during the fall.
(iv) What happens to the total Mechanical energy when the body hits the ground?​

Answer 1

answer:

Gravitational potential energy is given by the expression,

W = m g h

where,

h = Height above the ground = 10 m

m = Mass of the object = 50 kg

g = Acceleration due to gravity = 10 ms-2

W = 50 × 10 × 10 = 5000 J.

At half-way down, the potential energy of the object will be, begin mathsize 12px style 5000 over 2 space equals space 2500 space straight J end style  

At this point, the object has an equal amount of potential and kinetic energy. This is due to the law of conservation of energy. Hence, half-way down, the kinetic energy of the object will also be 2500 J.