Question

a body of mass 250g is initially at rest at a height 20m above the ground . taking g =10m/s^2 find its i) initial p.e and ii)k.e​

Answer 1

Answer :-

Given :-

• Mass, m = 250 g = 0.25 kg
• Initial velocity, u = 0 m/s
• Height, h = 20 m
• Acceleration due to gravity, g = 10 m/s²

To find :-

• Potential energy - P.E.
• Kinetic energy - K.E.

Solution :-

Calculating Potential energy :-

• m = 0.25 kg
• h = 20 m
• g = 10 m/s²

Substituting the value in formula :-

P.E. = mgh

$\sf = 0.25 \times 20 \times 10$

$\sf = 25 \times 2$

$\sf = 50 J$

Potential energy = 50 J

Calculating Kinetic energy :-

As the body is initially at rest, the kinetic energy of the body equals to 0.

Kinetic energy = 0 J