Question

A Car is moving with a Velocity 54km/h.The Kinetic energy of a boy of mass 40 kg sitting in the car is​

Answer 1

Answer:

300joule

Explanation:

1. K.E=1/2mv^2
2. v=54km/h=15m/sec
3. K.E.= 1/2×15×40
4. K.E.= 300joule

Answer 2

Answer: there are 2 answer depending on what question want to ask 300 and 0

Explanation: velocity of man = 54 km /hr =54 X 5/18 m/sec=15 m/sec

wrt man outside the car

kinetic energy of the boy = 1/2 (mass of boy)(velocity of the car)

=1/2(40)(15)=300

but wrt man sitting inside the car

K.E=1/2(40)(0) = 0 as both the boy and the man sitting in the car has velocity = 54 so relative velocity will be 0