SPH3U - Energy problem set 1. List all the energy transformations that take place while cooking food in a microwave oven. 2. A student pushes a 12.0 kg box along the ground with a force of 320N. It travels a distance of 14.0m in 8.0s a) how much work has the student done on the box? b) how much power has the student generated? 3. Marty kicks a 0.45 kg soccer ball. At the peak of its flight, it is travelling at 25 m/s and it's 12m above ground a) determine the kinetic energy of the soccer ball at its peak. b) determine the gravitational potential energy of the ball at its peak? 4. A 76.0 g apple falls from a tree branch 3.85m above the ground. How fast is it travelling when it hits the ground? Assume no air resistance. 5. A 5.40kg remote controlled car is travelling at 4.0 m/s just before it hits a ramp that will direct it straight up. a) what is the kinetic energy of the car before it hits the ramp? b)if it hits the ramp and is directed straight up at 4.0 m/s, how high will the car get above the top of the ramp before it comes to a stop and falls back down? Assume no friction or air resistance. 6. A student lifts a 10.0 kg box up to a height of 2.0 m by exerting an upward force of 120N on it. Determine the % efficiency of the student