Question

Joe pushes a box rightward with a force of 3 N, causing it to slide 2m across the floor at a constant speed. 1) How many joules (J) of work did Joe do on the box?Answer: _______ J2)How much work (in J) was done by friction on the box?Answer: ________ J

Answer 1

Given:

The force applied to the box is F = 3 N

The displacement of the box is d = 2 m

The box moves with constant speed.

Required:

1) Work done by Joe on the box.

2) Work done by friction on the box.

Step-by-step explanation:

1) The work done by Joe on the box can be calculated as

`\begin{gathered} W=Fd \\ =3*2 \\ =\text{ 6 J} \end{gathered}`

2) The box moves at a constant speed, so the acceleration will be zero.

The equation of motion can be written as

`\begin{gathered} F-f=ma \\ F-f=m*0 \\ F-f=0 \\ F=f \end{gathered}`

Here, f is the force of friction and m is the mass of the box.

The work done by friction can be calculated as

`\begin{gathered} W=fd \\ =3*2 \\ =6\text{ J} \end{gathered}`

Final Answer:

1) Work done by Joe on the box is 6 J.

2) Work done by friction on the box is 6 J.