A truck of mass 8000 kg is moving with a velocity of 50 km/h and collides with a bus of mass 5000 kg coming from opposite direction with a velocity of 45 km/h. After collision they stacked together and started to move in combined.
a. Define friction.
b. Why walking is difficult in a muddy street?
c. On the basis of stem calculate the combine velocity and direction.
d. Does the collision elastic? Explain mathematically.​