Question

which of the following scenarios has no work being done? *
1 point
flicking a tiny bug off your piece of paper.
a waitress carrying your food to your table.
crushing a can with your head.
pulling a fish out of the water by grabbing the fishing line with your hand to pull up.

Explanation:

To determine when work is not done, we use the physics definition of work: \( W = F \cdot d \cdot \cos(\theta) \), where \( F \) is force, \( d \) is displacement, and \( \theta \) is the angle between them. Work is done only if a force causes displacement in the direction of the force (or a component of it).

• Flicking a bug: Force is applied, and the bug displaces ( \( \theta = 0^\circ \), \( \cos(0^\circ)=1 \) ), so work is done.
• Waitress carrying food: The force (upward, to counter gravity) and displacement (horizontal) are perpendicular ( \( \theta = 90^\circ \), \( \cos(90^\circ)=0 \) ). Thus, no work is done on the food (though work is done against friction, the question focuses on the food’s displacement relative to the upward force).
• Crushing a can: Force is applied, and the can compresses (displacement in the force’s direction), so work is done.
• Pulling a fish: Force (upward) causes upward displacement, so work is done.

Answer:

B. A waitress carrying your food to your table.