At the same instant that a 0.50-kg ball is dropped from 25 m above earth, a second ball, with a mass of 0.25 kg, is thrown straight upward from earth's surface with an initial speed of 15 m/s. they move along nearby lines and pass without colliding. at the end of 2.0 s the acceleration of the center of mass of the two-ball system is? a 4.0-n puck is traveling at 3.0 m/s. it strikes an 8.0-n puck, which is stationary. the two pucks stick together. their common final speed is?

This energy transformation diagram represents the energy of a skateboarder moving along a half-pipe. as she skates toward the top of the half-pipe, her original kinetic energy is converted to potential energy and friction. how much of the energy is potential?

You want to lose weight and have been trying to decide which type of fad diet is best for you. you ask your doctor, who responds that a. fad diets are a temporary fix but generally don't have any side effects b. fad diets can be used several times a year to maintain a healthy weight c. fad diets can be risky for your health and, in the long run, do not work d. fad diets should never be used one right after the other; there should be a break between them select the best answer from the choices provided. a b c d

The great sandini is a 60.0-kg circus performer who is shot from a cannon (actually a spring gun). you don’t find many men of his caliber, so you him design a new gun. this new gun has a very large spring with a very small mass and a force constant of 1100 n/m that he will compress with a force of 4400 n. the inside of the gun barrel is coated with teflon, so the average friction force will be only 40.0 n during the 4.00 m he moves in the barrel. at what speed will he emerge from the end of the barrel, 2.50 m above his initial rest position?