Question

A car moving at 5.73 m/s with a mass of 1,176 kg runs into a brick wall. If the car comesto rest over 19.9x10s during the collision, what is the force of the wall on the car?

Answer 1

3.17 x 10^5 N

Step-by-step explanation:

The impulse is defined as the change in momentum:

`I=m\Delta v`

which is related to the force applied over time t:

`I=Ft`

therefore,

`m\Delta v=Ft`

Now in our case, the momentum of the car goes from some value to zero in 19.9 x 10^-3 s; therefore,

t = 19.9 x 10^-3, m = 1176 kg and Δv = 5.73 - 0 = 5.73 m/s.

Putting the above values into the equation gives

`1176(5.73)=F(19.9*10^(-3))`

dividing both sides by 19.9 x 10^-3 gives

`F=(1176\cdot5.73)/(19.9*10^(-3))`

which evaluates to give

`F=317,343\; N`
`\boxed{F=3.17*10^5N}`

which is our answer!