91Ó°ÊÓ

The given data can be listed below as-

• The force by which the boat has been pulled is, 130 N.
• The distance through which the boat has been pulled is, 6 m .
• The force needed to slow down the boat is,40 N .
• The distance opposite to the movement of the boat is, 5 m.

The work done for an object can be determined by taking the product of force applied on the object and the distance by which the object due to the application of force.

The equation of the work done is given as follows,

$W=Fd$ ..(1)

Here, F is the force required to be exerted on the object and d is the distance by which the object moved from its position.

For$F=130N$ and$d=6m$ in equation (1).

role="math" localid="1654146885708" $$\begin{gathered} W_1=\left(130N\right)×\left(6m\right) \\ =780Nm \\ =780Nm×\frac{1J}{1Nm} \\ =780J \end{gathered}$$

Thus, the work done is $+780J$.

For$$\begin{gathered} F=\left(-40N\right)×\left(5m\right) \\ =200Nm×\frac{1J}{1Nm} \\ =200J \end{gathered}$$ and in equation (1).

Thus, the work done is$-200J$ .

(c)

The total amount of work done is expressed as,

$W=W_1+W_2$

Substituting all the values in the above equation.

$$\begin{gathered} W=\left(+780J\right)+\left(-200J\right) \\ =580J \end{gathered}$$

Thus, the total amount of work done is$580J$ .