Question

A stone of mass 4.5Kg is dropped from a building. At the top of the building at rest, its energy is 2500J. calculate the height of the building

Answer 1

• Let the height of the building be h

• Mass of the stone, m = 4.5 kg

• The energy of the stone at the top of building when at rest, E = 2500 J

Since the stone is at rest, it possesses potential energy. It is the energy obtained by virtue of its position.

Potential energy, E = mgh

Where g is the acceleration due to gravity, g = 10 m/s²

$2500 = 4.5 \times 10 \times h \\ \\ 2500 = 45 \times h \\ \\ h = \frac{2500}{45} \\ \\ h = \frac{500}{9} \\ \\ h = 55.56 \: m$

The height of the building is 55.56 m.

Answer 2

Answer:

Given :-

• A stone of mass 4.5 kg is dropped from a building.
• At the top of the building at rest, its energy is 2500 J.

To Find :-

• What is the height of the building.

Formula Used :-

★ P.E = mgh ★

where,

• P.E = Potential Energy
• m = Mass
• g = Acceleration due to gravity
• h = Height

Solution :-

Given :

• Mass = 4.5 kg
• Potential energy = 2500 J
• Acceleration due to gravity = 10 m/s²

According to the question by using the formula we get,

⇒ P.E = mgh

⇒ 2500 = 4.5 × 10 × h

⇒ 2500 = 45 × h

⇒ 2500 = 45h

⇒ 45h = 2500

⇒ h = 2500 ÷ 45

➠ h = 55.56 m

∴ The height of the building is 55.56 m .