What is the name for potential difference that causes current to flow?

Explain the origin of the leap year. Why is it necessary?

What three things happen when air is warmed? a) it expands b) it contracts c) it becomes lighter d) it becomes heavier e) it rises f) it sinks

A cyclist rides 8.0 km east for 20 minutes, then he turns and heads west for 8 minutes and 3.2 km. Finally he rides east for 16 km, which takes 40 minutes. (a) What is the final displacement of the cyclist? (b) What is his average velocity?

A car traveled 1025 km from El Paso to Dallas iin 13.5 hr. What was its average velocity

If we describe the motion of a train as 110 km/h to the south, we are describing the train's A. velocity B. acceleration C. average speed

11. Which of the following best explains velocity? A. The direction of an object in motion B. Only the change of direction of an object in motion C. The speed and direction of an object in motion D. The speed of an object in motion

Using 6400 km as the radius of Earth, calculate how high above Earth's surface you would have to be in order to weigh 1/16th of your current weight. Show all work leading to your answer OR describe your solution using 3 - 4 complete sentences.

Which of these could occur if a switch is closed? A. A light bulb will light up. B. A hair dryer will turn off. C. A computer will shut down. D. B and C

When you throw a ball the work you do to accelerate it equals the kinetic energy the ball gains?

Old-fashioned heating systems sent steam into radiators in each room of a house. in the radiators, the steam condensed back to water. analyze this process and explain how it heated a room.