Question

Two automobiles, each of mass 500 kg, are moving at the same speed, 10 m/s, when they collide and stick together. In what direction and at what speed does the wreckage move (a) if one car was driving north and one south; (b) if one car was driving north and one east

thank you!!!

Answer 1

Here in the question they mentioned that the two automobiles stick together after their collision. Then this is a case of perfectly inelastic collision. Then in perfectly inelastic collision the linear momentum will be conserved. Momentum is a vector quantity so it has both magnitude and direction. We know that momentum is mass × velocity . Then by conservation of linear momentum we can write

Where M1 and M2 are the masses of two automobiles and V1 and V2 are it's velocities before collision and Vf is the final velocity of the two automobiles after collision. The detailed solution is shown below as an image .

So in first case ie a) The automobiles doesn't move after collision. But in second case ie b) they are move to North East direction with a velocity of 7.07 m/s.

Hope you ok with this and thank you .