An 800.0 kg car containing an 80.0 kg crash dummy is moving at 15 m/s. The car is smashed into a concrete walls and stops in 6.00x10^-2 seconds.
What is the change in momentum of the car?
The car lost all its momentum if it stopped
800*15
The dummy may have stopped and may have kept going through the windshield for all we know so it is not part of the problem (unless there s a part B which you have not gotten to yet.)
Or perhaps that is part C because surely the problem also wants to know the average force on the car which is (change in momentum / time)