Work equal to 136.0 Joules is expended in moving \(8.5 \times 10^{18}\) electrons between two points in an electric circuit. What potential difference does this establish between the two points?
A ball is thrown into the air. At the highest point, the ball has zero velocity and zero acceleration. Is this true or false, and why?
Answer (2)
Voltage = joules/coulomb
1 coulomb = 6.25 x 10^18 electrons 8.5 x 10^18 electrons = 1.36 coulombs
136 joules / 1.36 coulombs = 100 volts
The statement regarding the ball is false . Any object that's not hanging from something or resting on something is accelerating downward on account of gravity. No matter what direction you throw the ball, or how hard, its acceleration is 9.8 meters per second^2 directed downward, from the instant it leaves your hand until it hits the ground.
The potential difference established is approximately 100 volts, calculated from the work done in moving the electrons. The statement about the ball is false; it has zero velocity at its highest point but still experiences downward acceleration due to gravity.
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