Most of the skid mearks left at the scence of an automobile accident are left by the car tires after the collision occurs. How can measuring the direction and length of these skid marks. After the collision reveal whether either of the cars involved was speeding before the collision?

In the "before" part of Fig., car A (mass 1100 kg) is stopped at a traffic light when it is rear-ended by car B (mass 1400 kg). Both cars then slide with locked wheels until the frictional force from the slick road (with a low mu_k of 0.10) stops them, at distances d_A = 8.2 m and d_B = 6.1 m. What are the speeds of (a) car A and (b) car B at the start of the sliding, just after the collision? (c) Assuming that linear momentum is conserved during the collision, find the speed of car B just before the collision. (d) Explain why this assumption may be invalid.

According to a FIR in police station, car A was at rest waiting for a red light at a crossing when it was hit by similar car B from rear side. Both cars had then hard brekes on, and from their skid marks it is surmiesed that they skidded together about 8m in the original direction of travel before coming to rest. Assuming a stopping force of about 0.4 times the combined weights of the cars. the speed of car B just before the collision is approximately [g=10 m//s^(2)]

According to a FIR in police station, car A was at rest waiting for a red light at a crossing when it was hit by similar car B from rear side. Both cars had then hard brekes on, and from their skid marks it is surmiesed that they skidded together about 8m in the original direction of travel before coming to rest. Assuming a stopping force of about 0.4 times the combined weights of the cars. the speed of car B just before the collision is approximately [g=10 m//s^(2)]

According to a FIR in police station, car A was at rest waiting for a red light at a crossing when it was hit by similar car B from rear side. Both cars had then hard brekes on, and from their skid marks it is surmiesed that they skidded together about 8m in the original direction of travel before coming to rest. Assuming a stopping force of about 0.4 times the combined weights of the cars. the speed of car B just before the collision is approximately [g=10 m//s^(2)]