Question

Which has a greater momentum and greater kinetic energy-a truck with

a mass of 3530 kg moving at a speed of 21 m/s or a car with a mass of
1620 kg moving at a speed of 54 m/s? Answers below are given in the
form: greater momentum, greater kinetic energy.

Answer 1

the car has greater momentum.

the car has greater kinetic energy.

Step-by-step explanation:

FOR MOMENTUM:

Momentum is given as the product of mass and velocity of an object:

`P = mv`

where,

P = momentum

m = mass

v = velocity

For Truck:

`P_(truck) = (3530\ kg)(21\ m/s)\\P_(truck) = 74130 Ns`

For Car:

`P_(car) = (1620\ kg)(54\ m/s)\\P_(car) = 87480\ Ns`

Therefore, car has greater momentum.

FOR KINETIC ENERGY:

Kinetic Energy is given as:

`K.E = (1)/(2) mv^(2)`

where,

K.E = Kinetic Energy

m = mass

v = velocity

For Truck:

`K.E_(truck) = (1)/(2) (3530\ kg)(21\ m/s)^(2)\\K.E_(truck) = 778365\ J = 778.36\ KJ`

For Car:

`K.E_(truck) = (1)/(2) (1620\ kg)(54\ m/s)^(2)\\K.E_(truck) = 2361960\ J = 2361.96\ KJ`

Therefore, car has greater kinetic energy.