Question

Julie is holding a 5 kg book 1 m above the ground, Bob is holding a 10 kg book 2 m above the ground and Anna is holding a 7.5 kg book 1 m above the ground. All three students hold their book steady without moving for 5 minutes. Rank from greatest to least the amount of work being done by each person during this 5 minute period. (use > to indicate one value is greater than another, use = to indicate they are the same.)

Answer 1

All the three persons do no work while holding the books steady at their respective positions.

Step-by-step explanation:

The work done by a force is given by

`W=\overrightarrow{F}.\overrightarrow{dr}`

Since there is no dispalcement of the books we have work done equals

`W=\overrightarrow{F}.0\\\\\therefore W=0`