Question

. Find the increase in kinetic energy of a body of mass 600 gram when its speed increases from 2 metre

per second to 4 metre per second
​

Answer 1

Answer:

3.6 joule

Explanation:

change in KE=1/2 m(V -v)2

Answer 2

Given :

• Mass of the body(m) = 600 g = 0.6 kg

[ In order to convert g into kg divide by 1000]

• Initial velocity (u)= 2 m/s
• Final velocity(v) = 4 m/s

To find :

• Increase in kinetic energy

How to solve :

• Substitute the given vales in the formula to get the initial and final kinetic energy . Then simply , subtract in order to find the increase in kinetic energy .

Solution :

Kinetic energy is the energy possesed by the body due to it's motion .

⇒ KE = ½ mv²

Initial kinetic energy

⇒ KE = ½ m u²

Now let's substitute the given values in the above equation ,

⇒ KE = ½ x 0.6 x 4

⇒ KE = 1.2 J

Final kinetic energy

⇒ KE' = ½ m v²

Now let's substitute the given values in the above equation ,

⇒ KE' = ½ x 0.6 x 16

⇒ KE = 4.8 J

Increase in kinetic energy

⇒ ΔKE = KE' - KE

⇒ ΔKE = 4.8 - 1.2

⇒ ΔKE = 3.6 J

The increase in kinetic energy is 3.6 J .