Question

An object of mass 2kg raised to a height 10m possess potential energy of 200J. What is the kinetic energy and potential energy at a height 4 metre? ​

Answer 1

Given:-

• Mass of Object = 2kg

• Height given = 10m

• Potential energy = 200J

To Find:-

• The Kinetic energy and Potential energy at a height of 4m

Formulae used:-

• P. E = mgh.

Now,

• Firstly we will find the Potential energy at a height of 4m.

• We know that energy is conserved. So, the loose in Potential energy is equal to gain in kinetic energy.

Therefore,

→ Potential energy = mgh

→ P. E = 2 × 10 × 4

→ P. E = 80J

Hence, The Potential energy at a height of 4m is 80J

Now, According to concept the Kinetic energy will be 200 - 80 = 120J

Therefore, The Kinetic energy of object af a height of 4m is 120J.

Answer 2

${\bold{\sf{\underline{Understanding \: the \: concept}}}}$

✠ This question says that there is an object and its mass is 2 kg ; it's raised to a height 10 m and possess potential energy of 200 J. Now this question ask us to find the kinetic energy and the potential energy at a height 4 metre.

${\bold{\sf{\underline{Given \: that}}}}$

✰ Mass = 2 kilograms

✰ Raised height = 10 metres

✰ Posses potential energy = 200 Joules

${\bold{\sf{\underline{To \: find}}}}$

✰ Kinetic energy at a height 4 metre

✰ Potential energy at a height 4 metre

${\bold{\sf{\underline{Solution}}}}$

✰ Kinetic energy at a height 4 metre = 120 J

✰ Potential energy at a height 4 metre = 80 J

${\bold{\sf{\underline{Using \: concepts}}}}$

✰ Potential energy formula.

${\bold{\sf{\underline{Using \: formula}}}}$

✰ Potential energy = mgh

${\bold{\sf{\underline{We \: also \: write \: these \: as}}}}$

✰ Potential energy as P.E

✰ Mass as m

✰ Joules as J

✰ Height as h

✰ Raised height as g

${\bold{\sf{\underline{Full \: solution}}}}$

✠ Let us find the Potential energy.

↦ Potential energy = mgh

↦ Potential energy = 2 × 10 × 4

↦ Potential energy = 20 × 4

↦ Potential energy = 80 J

✠ Now according to the question let us find the kinetic energy

↦ Kinetic energy = Posses potential energy - Finded potential energy

↦ Kinetic energy = 200 J - 80 J

↦ Kinetic energy = 120 Joules