Question

880 kilogram car traveling East at 15 meters per second collides with a 750 kg car traveling north at 20 meters per second the cars stick together. in what direction does the wreckage move just after the Collision.

please show all work so I can actually learn this. thanks.

Answer 1

Consider east as x-axis and north as y-axis.
Initial momentum of the 880 kg car, P1 = 880 x 15
= 13200 kg m/s
Initial momentum of the 750 kg car, P2 = 750 x 20
= 15000 kg m/s

Total initial momentum, Pi = P1 + P2
= 13200 kg m/s + 15000 kg m/s
Using momentum conservation, Final momentum = Initial momentum
Final momentum, Pf = 13200 kg m/s + 15000 kg m/s
tan = Pf_y/Pf_x
= 15000 / 13200
= 1.136
= tan^-1(1.136)
= 48.65 degrees anti-clockwise with respect to x-axis (east)