Question

A 1,500 kg car and a 30,000 kg truck are both moving 30 m/s north . Which vehicle has the larger momentum ? Explain reasoning .

Answer 1

Answer:

Momentum of truck is larger than momentum of car since mass of truck is larger than that of car.

Explanation:

Given:

mass of a car $m_{car}$ = 1500 kg

mass of truck $m_{truck}$ = 30000 kg

velocity of car = velocity of truck = v = 30 m/s

To find: momentum of car and truck

We know that momentum (p) is measure of moving object which is calculated using formula:

                p = mv, where m is mass and v is velocity.

From the above equation it is inferred that the momentum depends on mass and velocity of the body. In given problem velocity is constant, hence higher mass body has more momentum. Mass of truck is greater than that of car hence truck has larger momentum

This can also be proved by calculating the momentum each vehicle:

momentum of car $p_{car}$ = $m_{car}$ * v

                                     = 1500 kg * 30 m/s

                                     = 45000 kg.m/s

momentum of truck $p_{truck}$ = $m_{truck}$ * v

                                           = 30000 kg * 30 m/s

                                           = 900000 kg.m/s

momentum of truck $p_{truck}$  > momentum of car $p_{car}$

Hence proved.