Question

The kinetic energy of an object of mass, m moving with a velocity of 10 m/s is 50 J . What will be its kinetic energy when its velocity is doubled ? What will be its kinetic energy when its velocity is increased three times ?​

Answer 1

Answer:

We know that K.E

= \frac{1}{2} mv^221mv2

⇒ K.E = \frac{1}{2} mv^221mv2

⇒ 25 = \frac{1}{2}21 m 5^252

⇒ m = 2 kg

1st Case

If velocity is doubled

then,

velocity of the object = 10 m/s

mass os the object = 2 kg

⇒ K.E = \frac{1}{2} mv^221mv2

⇒ K.E = \frac{1}{2}21 2 × 10²

⇒ K.E = 100 joule.

2nd Case

If velocity is three times

Then,

velocity of the object = 15 m/s

mass os the object = 2 kg

⇒ K.E = \frac{1}{2} mv^221mv2

⇒ K.E = \frac{1}{2}21 2 × 15²

⇒ K.E = 225 joule.

Hence, kinetic energy  when its velocity is increased three times 225 J.