Question

which of these is an example of work being done?
pushing a chair and it slides across the floor
holding a book still
standing with a backpack
sitting on a bench
question 4 (1 point) saved
what is the formula for work?
force + time
force ÷ distance
power x time
force x distance

Explanation:

• For the first question: Work is done when a force causes an object to move in the direction of the force. Pushing a chair and it slides across the floor involves a force (push) and displacement (chair moving), so work is done. Holding a book still, standing with a backpack, and sitting on a bench involve no displacement in the direction of the force (force of holding/standing/sitting is countering gravity, but no movement in that direction), so no work is done.
• For the second question: The formula for work is \(W = F\times d\) (Work = Force × Distance). Power \(P=\frac{W}{t}\), so \(W = P\times t\) is also correct as \(W = (\frac{W}{t})\times t\).

Answer:

• First question: Pushing a chair and it slides across the floor
• Second question: Power x Time, Force x Distance