Question

A 0.2 kg plastic cart and a 20 kg lead cart can both roll without friction on a horizontal surface. Equal forces are used to push both carts forward for a time of 1 s, starting from rest. After the force is removed at t = 1 s, the momentum of the plastic car is _____ the momentum of the lead car.

Answer 1

Answer:

The momentum of the plastic car is same the the momentum of the lead car.

Explanation:

Given that,

Mass of plastic car = 0.2 kg

Mass of lead = 20 kg

Time = 1 sec

Equal forces are used to push both carts

$F_{p}=F_{l}$

We need to calculate the momentum

Using formula of momentum

$P=mv$

$P=m\times a\times t$

$P=m\times\dfrac{F}{m}\times t$

$P=F\times t$

Put the value into the formula

For plastic cart,

$P_{p}=F\times 1$...(I)

For lead cart,

$P_{l}=F\times 1$...(II)

Divided equation (I) by equation (II)

$\dfrac{P_{p}}{P_{l}}=\dfrac{F\times 1}{F\times 1}$

$\dfrac{P_{p}}{P_{l}}=\dfrac{1}{1}$

Hence, The momentum of the plastic car is same the the momentum of the lead car.