a parent pulls a sled and rider with a combine weight of 50kg up a 20-meter high hill and then gives the sled a push, providing an initial velocity of 4m/s. Frictional forces acting on the sled do 2000 joules of negative work as the sled moves down the hill. Find the total energy of this system.

1400 kg car has a speed of 27 m/s. if it takes 7 s to stop the car, what is the impulse and the average force acting on the car?

Any color picture tube and electric field exerts a net force of magnitude 1.68x 10^-13 n on an electron the rest mass of an electron is 9.11 x 10^-13 what is the electron acceleration?

Acylinder with a movable piston contains 11.7 moles of a monatomic ideal gas at a pressure of 1.32×10^5 pa. the gas is initially at a temperature of 300 k. an electric heater adds 43200 j of energy into the gas while the piston moves in such a way that the pressure remains constant. cp=20.79 j k^−1 mol^−1 for a monatomic ideal gas, and that the number of gas molecules is equal to avogadro's number (6.022×10^23) times the number of moles of the gas. (a) what is the temperature of the gas after the energy is added? (b) what is the change in volume of the gas? (c) how much work is done by the gas during this process?