Question

a student pushes a heavy box across a floor with a constant force of 100 n. the box moves 5 meters. how much work is done? work = force x distance
10 j
100 j
500 j
1000 j
which scenario represents a situation where work is not being done in the physics sense?
a person lifting a heavy weight above their head
a book sliding down an inclined plane
a student holding a heavy backpack while standing still
a car accelerating on a straight road

Explanation:

Step1: Calculate work done

Work formula \(W = F\times d\). Given \(F = 100\ N\) and \(d = 5\ m\).
\(W=100\times5\)

Step2: Compute the value

\(W = 500\ J\)

For the second question:

Work is done when a force causes displacement. In the case of a student holding a heavy backpack while standing still, there is a force (gravity acting on the backpack, and the student exerting an upward force to hold it) but no displacement in the direction of the force. While lifting a weight (displacement against gravity), a book sliding (displacement due to force of gravity component along the incline), and a car accelerating (displacement due to force from engine) all involve force - displacement.

Answer:

First question: \(500\ J\) (third option). Second question: A student holding a heavy backpack while standing still.