Question

A force of F= 45 N is used to drag a crate 3 m across a floor.

Answer 1

(a) 108 J

(b) 0 J

(c) 108 J

Explanation:

(a)

Express the relation between horizontal component of work done and force on the crate:

`W_h=F_h\cdot d`

Here Wh is the horizontal component of the work done on the crate and Fh is the horizontal component of force and d is the distance of the crate across the floor.

Replacing:

`\begin{gathered} W_h=36\cdot3 \\ W_h=108\text{ J} \end{gathered}`

(b)

Express the relation between vertical component of work done and force on the crate:

`W_v=F_v\cdot d`

Here Wv is the vertical component of the work done on the crate and Fv is the vertical component of force and d is the distance of the crate across the floor.

Replacing:

`\begin{gathered} W_h=27\cdot0 \\ W_h=0\text{ J} \end{gathered}`

(c)

Express the relation for total work done by the 45 N force:

`\begin{gathered} W_{\text{total}}=W_h+W_v \\ \text{ replacing} \\ W_{\text{total}}=108+0 \\ W_{\text{total}}=108\text{ J} \end{gathered}`