Question

1. choose the correct answer.

in a ______ wave, energy moves back and forth in the same direction as the wave.
longitudinal
transverse

1. choose the correct answer.

in which of the following examples has work been done?
pushing a house with both hands
pulling a door handle and the door does not move
pushing a wagon up a hill
pulling a parked bus with one hand

Explanation:

For question 11:

• In a longitudinal wave, particles (and thus energy) move parallel (back - and - forth) to the direction of wave propagation.
• In a transverse wave, particles move perpendicular to the wave direction.

For question 12:

• Work is done when a force causes a displacement.
• Pushing a house with both hands: no displacement (house doesn't move), so no work.
• Pulling a door handle and the door does not move: no displacement, so no work.
• Pushing a wagon up a hill: force is applied and there is a displacement in the direction of the force (up the hill), so work is done.
• Pulling a parked bus with one hand: no displacement (bus doesn't move), so no work.

Answer:

1. longitudinal
2. pushing a wagon up a hill