Question

a car and truck both having same linear momentum which one have greater kinetic energy?

Answer 1

heya. .
Answr..

A car and a lorry have the same momentum. Which will have greater kinetic energy?

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4 ANSWERS



Satya Parkash Sud, M.Sc. Physics & Nuclear Physics, University of Delhi (1962)

Answered Jul 25 2017 · Author has 1.4k answers and 542.9k answer views

Originally Answered: A car and a lorry have the same momentum. Which will have greater kinetic energy?

Let the car have a mass m and move with a velocity V. Let the lorry have a mass M and move with a velocity v. Then,

Momentum of the car = m V,

Momentum of the lorry= M v

Since the two momenta are equal we have,

mV = M v = p ( p is magnitude of momentum)

Kinetic energy of the car = p²/2m,………1

Kinetic energy of the lorry= p²/2M, … ….2

Comparing equations 1 and 2,

Kinetic of the car › Kinetic energy of the lorry ( as the kinetic energy of the vehicle is inversely proportional to the mass of the vehicle. A lighter vehicle has larger kinetic energy. Because to have the same momentum a lighter vehicle needs to travel much faster. 

Answer 2

hai there
I think it will be car because both have same linear momentum because mass of car is less now kinetic energy =P^2/2m so momentum is same so square of momentum will also same and now because K.E. is inversely proportional to mass will have more kinetic energy
please mark it as branlist ans