Question

1. A body of mass 5 kg is taken from a height 5 m
to 10 m. Find the increase in its potential energy
(g = 10 m s-2).​

Answer 1

Answer:

• 250 J

Explanation:

Given

• Mass (m) = 5 Kg
• Height (h₁) = 5 m
• Height (h₂) = 10 m
• Acceleration due to gravity (g) = 10 m/s²

To find

• Increase in potential energy.

Solution

Increase in P.E:

• mg (h₂ - h₁)
• 5(10) (10 - 5)
• 50 (5)
• 250

∴ Increase in potential energy is 250 J

Answer 2

Mass of the particle = 5 kgs

Initial height = 5 m (h)

Final height = 10 m (H)

g = 10 m/s²

We know, PE (gravitational) = mgh

∴ ∆PE = mgH - mgh = mg(H - h)

⇒ ∆PE = (5 kg)(10 m/s²)(10 m - 5 m)

⇒ ∆PE = 25 × 10 Nm

⇒ ∆PE = 250 J (answer).