4.3.3 Calculating Potential Energy

Question 1

Calculating Potential Energy

Answer 1

• The general formula for the change in potential energy for an arbitrary force is .
• The change in potential energy due to gravity is , where Dy is the change in distance from the Earth’s surface.
• The potential energy of a spring is , where xis the displacement of the spring

Question 2

Which of the following does not have an associated potential energy?

Answer 2

Friction

Question 3

A conservative force is given by the formula F = Qx^2, where Q is a constant. Which of the following is the potential energy associated with this force, assuming the potential energy is zero at x = 0?

Answer 3

U = -1/3Qx^3

Question 4

Which of the following is true based on the equation

delta U = - integral from xi to xf of Fxdx

Answer 4

Fx = -dU/dx

Question 5

True or false?

All conservative forces have a related potential energy.

Answer 5

true

Question 6

Which of the following statements is correct?

Answer 6

The change in potential energy is the opposite of the integral of the force with respect to distance.

Question 7

Which of the following is not a reason why the change in potential energy is more useful than potential energy when calculating the total energy of a system?

Answer 7

Energy must be conserved.

Question 8

Which of the following is true about delta U?

Answer 8

delta U = W (done against external forces)