Question

An object of mass 40 kg is raised to a height of 5 m above the
ground. What is its potential energy? If the object is allowed to
fall, find its kinetic energy when it is half-way down.​

Answer 1

Answer:As we know that ,

Potential energy =mgh

Take g= 10 m/s^2

Now ,

P.E = 40 ×10×5 =2000J

And K.E at half way = mgh

Where h is half means 2.5

K.E = 40 ×10×2.5

= 1000 J

Explanation:

Here ,J is joule that is unit of work done.And at the end K.E is equal to P.E so I took K.E equal to mgh

If answer is wrong or I went somewhere wrong just let me know

Answer 2

✬ Potential Energy = 2000J ✬

✬ Kinetic Energy = 1000J ✬

Explanation:

Given:

• Mass of the object is 40 kg.
• Object is raised to a height 5 m above the ground.

To Find:

• What is its potential energy?
• What is its kinetic energy when object is half way down?

Solution: We know that formula for finding potential energy is

★ Potential energy = mgh ★

• Putting values in Formula •

$\small\implies{\sf }$ 40 kg x 10 ms-² x 5 m

$\small\implies{\sf }$ 2000J

Hence, The potential energy is 2000J

• Using Law of conservation of Energy, K.E when it is half way down. •

$\small\implies{\sf }$ mgh/2

$\small\implies{\sf }$ 40 x 10 x 5/2

$\small\implies{\sf }$ 2000/2

$\small\implies{\sf }$ 1000J

Hence, its kinetic energy when object is half way down is 1000J