Chapter 10.1, Problem 7PP

a.

To determine

Work done by passenger on the box to carry up.

Answer to Problem 7PP

  $-903\text{J}$

Explanation of Solution

Given:

Weight of suitcase i.e. $F=215\text{N}$

Vertical displacement is $d_1=4.2\text{m}$

Horizontal displacement is $d_2=4.6\text{m}$

Formula used:

Since, $g$ works vertically downwards, but displacement is vertically downward.

Work done is given by,

  $W=Fd\cos \theta$

Here $\theta {\text{=180}}^o$

Calculation:

Putting the values

  $\begin{array}{c}W=-215\times 4.2\\ =-903\text{J}\end{array}$

b.

To determine

Work done by passenger on the box to carry down.

Answer to Problem 7PP

  $903\text{J}$

Explanation of Solution

Weight of suitcase i.e. $F=215\text{N}$

Vertical displacement downward is $d_1=4.2\text{m}$

Horizontal displacement is $d_2=4.6\text{m}$

Formula used:

  $g$ works vertically downwards.

Work done is given by

  $W=Fd\cos \theta$

Here, $\theta {\text{=0}}^o$

Calculation:

Putting the values

  $\begin{array}{c}W=215\times 4.2\times \cos 0^o\\ =903\text{J}\end{array}$