Question

6. The speed of a body of mass 4 kg increases
from 2 m/s to 4 m/s in a certain time interval
Find the increase in the kinetic energy of the
body.
(Ans. 24 J)​

Answer 1

Answer:

The mass of the body = 4 kg

The initial speed = 2 m/s

The final speed = 4 m/s

We need to find the increase in the Kinetic energy of the body.

The formula to find the Kinetic energy of a body is ½mv², where m is the mass of the body and the v is the speed or velocity of the body in motion.

Finding the Kinetic energy if the body with the initial speed of 2 m/s :

⇒ ½*m*v²

⇒ ½*4*(2)²

⇒ 2*4

⇒ 8 J

Finding the Kinetic energy if the body with the final speed of 4 m/s :

⇒ ½*m*v²

⇒ ½*4*(4)²

⇒ 2*16

⇒ 32 J

So, the increase in the Kinetic energy of the body = 32 - 8 = 24 J.

Answer 2

Your answer is 24J


Hope this helps