Question

Calculate the p.e. of a 5 kg mass when it is (i) 3 m, (ii) 6 m, above the ground. (g = 10 N/kg)

Answer 1

Given :

• Mass of the object = 5 kg.

• Acceleration due to gravity = 10 N/kg or 10 m/s².

• Height = h¹ = 3 m.

• Height = h² = 6 m.

To find :

Potential energy possessed by the body at two different heights.

Solution :

We know the formula for potential energy possessed by a body i.e,

⠀⠀⠀⠀⠀⠀⠀⠀⠀P·E = mgh

Where :

• P·E = Potential energy
• m = Mass of the body
• h = Height of the body

Potential energy of the body at height of 3 m :

By using the formula for Potential energy and substituting the values in it, we get :

==> P·E = mgh

==> P·E = 5 × 10 × 3

==> P·E = 150

∴ P·E = 150 J.

Hence the potential energy possessed by the body is 150 J.

Potential energy of the body at height of 6 m :

By using the formula for Potential energy and substituting the values in it, we get :

==> P·E = mgh

==> P·E = 5 × 10 × 6

==> P·E = 300

∴ P·E = 300 J.

Hence the potential energy possessed by the body is 300 J.