Question

Calculate the momentum of a 1,500 kg car traveling at 6 m/s.

A military airplane sometimes needs to refuel in mid-air, and another plane flies above it to add the fuel. If a plane with a mass of 7,800 kg is traveling with a velocity of 30 m/s and refuels by adding an additional 800 kg of jet fuel, what will its new velocity be? (Hint: This is a multi-step problem).

Answer 1

1. 9000 kg-m/s

2. 27.2 m/s

Answer 2

See the answers below.

Step-by-step explanation:

Momentum is defined as the product of mass by velocity, in this way we have the following equation.

`P=m*v`

where:

P = momemtum [kg*m/s]

m = mass = 1500 [kg]

v = velocity = 6 [m/s]

`P = 1500*6\\P=9000 [kg*m/s]`

Now we have to calculate the momentum of the plane when it travels at 30 [m/s].

`P_(airplane)=m_(plane)*v_(plane)\\P_(airplane)=7800*30\\P_(airplane)=234000[kg*m/s]`

Now this same momentum must be conserved, in such a way that the mass is increased but the velocity must decrease for the momentum to be conserved.

`P=m_(new)*v_(new)\\234000=(7800+800)*v_(new)\\234000=8600*v_(new)\\v_(new)=27.2[m/s]`