11.1.4 A Wave on a Rope: Energy and Power

Question 1

A Wave on a Rope: Energy and Power

Answer 1

• All waves carry energy.
• In a transverse wave on a rope, the kinetic and potential energies of the rope vary from point to point.
• The average power transmitted by a wave on a rope is given by the formula . The general features of this formula apply to all waves in all media

Question 2

If the frequency f of a traveling sine wave on a rope is doubled while the velocity and the amplitude are kept constant, how is the average power transmitted by the rope affected?

Answer 2

The power is quadrupled.

Question 3

Which of the following is the unit of power in the mks system?

Answer 3

• W (watts)
• J / s
• Nm / s

Question 4

Which of the following represents the magnitude of energy per wavelength?

Answer 4

1/2 u * wavelength * w^2A^2

Question 5

Waves, like particles, carry and transmit energy. Particles transmit energy by moving from one place to another. Waves also transmit energy by transferring matter.

Answer 5

false

Question 6

Which of the following represents the energy passing through point B per second? Assume that the energy contained in one wavelength is Ew

Answer 6

P = Ew f

Question 7

The energy of a physical system can be increased by doing work on it. Waves carry energy because work is done by some source that generates them. Work per unit time is referred to as ____________.

Answer 7

power

Question 8

The equation for average power is based on the special case of a transverse wave traveling on a rope. However, the dependence of P on two quantities on the right side of the equation holds for all waves. What are these quantities?

Answer 8

For any wave, P = A^2 and P = w^2

Question 9

A wave with a larger amplitude delivers more energy per unit time. How can the power delivered be doubled without changing anything in the system except the amplitude? Note: A is the original amplitude.

Answer 9

Increase the amplitude by a factor of sqrt(2) (sqrt(2)A)