At the same instant that a 0.5 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.mls. They move along nearby lines and pass without colliding . At the end o 2.0 s the velocity of the center of mass of the two-ball system is :

50 g of ice at 0°c is dropped in a beaker containing 100 g of water at 0°c. what will be the contents of the beaker after 5 hours? assume that the room temperature is 0°c.

Scout feels ill one day before school. her mother puts a thermometer in her mouth and the temperature begins to climb to 100°f. what is happening between the cooler thermometer and scout's body? a) scout's body is applying a force to the particles in the thermometer. b) kinetic energy is being transferred from her mouth to the thermometer. c) potential energy is being lost by the thermometer and gained by scout's body. d) the potential energy stored in foods is converted to mechanical energy to raise the mercury in the thermometer.

Suppose a wire with a current is pushed upward by a magnetic field. how would the wire move if the direction of the current reversed? explain your answer.