Question

two vehicles A and B of masses 1.5kg and 3.75 kg are moving with the same speed. which of the two has greater kinetic energy. why?​

Answer 1

Let :

• Speed of A = v
• Speed of B = v'

Given :

• Mass of A = 1.5 kg
• Mass of B = 3.75 kg
• Speed of A = speed of B

To find :

Which have greater kinetic energy

Formula used :

KE = (1/2) m × v²

Solution :

☆ KE of A = (1/2) × mass of A × (speed of A)²

➼ KE of A = (1/2) × (1.5) × v²

➼ KE of A = 0.75 v² ..... equation 1

☆ KE of B = (1/2) × mass of B × (speed of B)²

➼ KE of B = (1/2) × (3.75) × (v')²

As we know , speed of A = Speed of B

this gives , v' = v

➼ KE of B = 1.875 v² ........ equation 2

☆ From equation 1 & 2 , we can clearly see that,

KE of B is greater than KE of A

ANSWER :

KE of B is greater than KE of A

Additional information :

{ When speed is same KE depends on mass of body, more is mass more is KE }