Energy changes form all the time, but the total stays the same. In this course we follow this law in a falling ball and a swinging pendulum. Then we ask how fast work is done, which is power, and we learn to read an electricity bill.
3 lessons, about 1 h 15 min3 simulations12 problems6 practice questionsPython in every lesson
Created by StemPy LabEnergy changes from one form to another, but it is never made or destroyed. In a fall, the potential energy lost becomes kinetic energy, so the speed after a fall of is , whatever the mass.
Power is the work done in one second, , measured in watts. A machine with more power does the same work in less time. Power is also the rate at which energy is changed.
Electricity is sold in kilowatt hours, or units. One unit is the energy used by a appliance in , which is . Units are power in kW times time in hours, and the cost is units times the price of a unit.
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With Standard, you also open 10 more problems, 2 Python labs and 1 extra course. Everything you have used here stays free, always.