Question

A body of mass 20 kg is lifted upto 10 m height. Calculate the potential energy if the body is allowed to fall, find the potential enrgy just before it reaches the ground.​

Answer 1

Given:-

• Mass of body = 20kg

• Height of Body = 10m

• Acceleration due to gravity = + 10m/s²

To Find:-

• The Potential energy if the body is allowed to fall and P.E just before it reaches the ground.

Formulae used:-

• P.E = mgh

Where,

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

Now

→. P.E = mgh

→ P. E = 20 × 10 × 10

→ P. E = 2000J

Therefore, The Potential energy of body is 2000J.

When the body falls down its Kinetic energy increases and Potential enrgy decrease. before reaching in the ground it's Potential Energy totally converts into Kinetic Energy.

So,

→ The Potential energy just beforereaching the ground will be Zero.

Answer 2

Answer:

Given:-

Mass of the object (m) = 20 kg.

Height (h) = 10 m.

Acceleration due to gravity (g) = 10 m/s$^2{}$ (assuming)

To find:-

Potential energy of the body just before it reaches the ground.

Solution:-

We know that,

P.E = m × g × h

$\Longrightarrow$ P.E = 20 × 10 × 10

$\Longrightarrow$ P.E = 2000 J

Hence, potential energy of the body is 2000 J.

P.E just before it reaches the ground = 0.

$\fbox{Know More}$

What is potential energy?

Potential energy is the energy difference between the energy of an object in a given position and its energy at a reference position.

Potential energy is one of the main form of energy along with kinetic energy.

Examples of potential energy include:

• A rock sitting on the edge of a cliff. If the rock falls, the potential energy will be converted to kinetic energy, as the rock will be moving.
• A sparkler. The chemical potential energy in a sparkler will be released when the top of the stick is lit.