A RED toy car of mass 4.7 kg, hits BLUE toy car, with mass 1.2 kg, head-on. The blue car originally had a velocity of -15 m/s. After the two cars collide, they stick together and stop. What was the Red car's original velocity?

The system is released from rest with the cable taut, and the homogeneous cylinder does not slip on the rough incline. determine the angular acceleration of the cylinder and the minimum coeffi cient s of friction for which the cylinder will not slip.