A horizontal spring is compressed and a 4 kg block is placed on the left of the spring and a 7 kg block on the right. After the system is released from rest the 4 kg block slides to the left at 14 m/s and the 7 kg block slides to the right. The surface is frictionless. 33. The speed of the 7 kg block after it loses contact with the spring is

After a car's engine has been running for a while, if you stand near the car's engine you can often feel heat coming from the engine as a result of a. radiation b. convection c. conduction

A33.1 g copper object is launched from a 1.5 m 30° steel incline positioned on the floor by being pulled up a string attached to a 50.0 g mass suspended vertically over a pulley. the object is projected towards a glass table where it lands when it is at the point along its trajectory with the lowest speed. it comes to a halt when it clears the opposite edge of the table. it then falls and lands on 9 physics texts each 5 cm thick that are stacked on the floor on the opposite side of the table. assume that the table does not have a ledge and the rectangular object experiences 0.05 n of air resistance as it falls towards the books. how far and how long did the object travel and how fast does it hit the books. assume that at the moment the copper object leaves the incline, the massless string and ideal pulley break off

The percent efficiency of a machine can never be 100% (or greater), because in the real world some energy is always converted into a. heat b. work c. input force d. output force