Question

a car and a truck both have the same Momentum which one have greater kinetic energy explain

Answer 1

As kinetic energy is given by p^2/2m
kinetic energy is inversely proportional to mass
as mass of car is less than truck hence car will have more kinetic energy than truck.

Answer 2

Relation between kinetic energy and momentum is

K.E = P^2/2m

as both car and truck have same momentum but we are familiar that truck has greater mass as compared to car
So mass is greater if it is divided by momentum according to above relation kinetic energy will be less .

We came to a conclusion that truck will have less kinetic energy as compared to car.

For example if momentum is 20kgm/s

mass of car is 4kg (let) , and mass of truck is 5kg

Now solve this
Put these given values in K.E=P^2/2m

K.E of car = 20^2/2×4 (mass of car =4kg)
K.E of car = 400/8=50J

K.E of truck = 20^2/2×5 (mass of truck =5kg)
K.E of truck = 400/10=40J