I'm not sure how to figure this one out:
In a circuit with just a bulb, battery, and two wires, 3 amperes of current passes through the light bulb. The resistance of the light bulb is 1.5 ohms. What is the voltage of the battery?
I don't understand how kinetic energy works: How much kinetic energy does a car have when it moves at 100 km/hr, as compared with when it moves at 50 km/hr? The answer is 4 times as much, but why?
I don't understand this:
A slow car moves at a steady 10 km/hr down a straight highway while another car zooms past at a steady 120 km/hr. Which car is has the greater net force on it?
The answer is neither, because the net force on each car is zero.
Why is it zero?