A crate is pushed along a straight warehouse floor in three successive stages in the…

PHYSICS · Multi-part · AP · Physics C: Mechanics · Work Energy and Power · Work Energy and Power

Problem

A crate is pushed along a straight warehouse floor in three successive stages in the same straight line. (i) A constant horizontal force of

200\,\text{N}

moves the crate

6\,\text{m}

forward. Calculate the work done in this stage. (ii) The force is then reduced to

150\,\text{N}

and the crate is moved a further

4\,\text{m}

in the same direction. Find the additional work done during this stage. (iii) Finally, the crate is accidentally pushed

2\,\text{m}

back toward its starting point by a worker applying a horizontal force of

80\,\text{N}

opposite to the original forward direction. Compute the work done in this last stage, clearly indicating its sign. (iv) Determine the net work done on the crate after all three stages and comment on whether the overall work is positive, negative or zero.

Related theory

Browse the problem library