Question

A worker pushes a wheelbarrow with a horizontal force of $\mathbf{50}\mathit{N}$ on level ground over a distance of$\mathbf{5}\mathbf{.}\mathbf{0}\mathit{m}$ .If a friction force of $\mathbf{43}\mathit{N}$ acts on the wheelbarrow in a direction opposite that of the worker, what work is done on the wheelbarrow by the worker? (a) 250 J (b) 215 J (c) 35 J (d) 10 J (e)None of those answers is correct.

Short answer

The work done on the wheelbarrow by the worker is .$250\text{\hspace{0.17em}J}$

Step-by-step solution

Write the given data from the question.

The forces applied by the worker,$\text{F}=50\text{\hspace{0.17em}N}$

The frictional force,${\text{f}}_{\text{s}}=43\text{\hspace{0.17em}N}$

Distance travel by the wheelbarrow,$\text{S}=5\text{\hspace{0.17em}m}$

Determine the formulas to calculate the worker’s work on wheelbarrow

The expression to calculate the work done is given as follows.

$\mathit{W}\mathbf{=}\mathit{F}\mathit{S}\mathit{c}\mathit{o}\mathit{s}\mathit{\theta }$1)

Here, $\mathit{\theta }$ is the angle between the applied force and displacement.

Calculate the work done on wheelbarrow by the worker.

Since the applied force by the worker is in the direction of the displacement, the angle between the applied force and displacement would be zero.

$\text{θ}=0°$

Calculate the work done on wheelbarrow.

Substitute$5\text{\hspace{0.17em}m}$, for$\text{S}$,$50\text{\hspace{0.17em}N}$for $\text{F}$and $0°$ forinto equation (1).

$\begin{array}{c}W=50\times 5\cos 0°\\ =250\text{\hspace{0.17em}J}\end{array}$

Hence the work done on the wheelbarrow by the worker is .$250\text{\hspace{0.17em}J}$