A frictional force f provides the centripetal force as a car goes around an unbanked curve of radius R at speed V. Later, the car encounters a similar curve, except of radius 0.5 R , and the driver continues around this curve at the same speed V . In order to make this second curve, the frictional force on the car must be equal to In order to make this second curve, the frictional force on the car must be equal to:

Identical marbles are released from the same height on each of the following four frictionless ramps . compare the speed of the marbles at the end of each ramp. explain your reasoning

How is sound energy produced a. vibrating objects b. objects being heated c. temperature differences d. stationary objects

Diego is trying to lift a piano to the second floor of his house. diego uses a pulley system and gives a big lift to the piano. the piano moves upward, then stops, and then it starts to fall to the ground. which list best describes the forces on the piano in the proper order? positive force → balanced force → negative force negative force → balanced force → positive force positive force → unbalanced force → negative force negative force → unbalanced force → positive force