Question

in which case is work being done?
listening to music
pushing open a door
reading in a chair
birdwatching on a bench

Explanation:

To determine when work is done, we use the physics definition: work is done when a force causes displacement.

• "listening to music": No force causing displacement.
• "pushing open a door": A force is applied (pushing) and the door displaces (opens), so work is done.
• "reading in a chair": No force causing displacement (just sitting/reading).
• "birdwatching on a bench": No force causing displacement.

Answer:

B. pushing open a door