Question

1) What works is done when a person pushes a refrigerator weighing 720 N across a floor 12 m? (The force of friction between
the refrigerator and the floor is 480 N)​

Answer 1

Answer:

2880 J

Explanation:

because of frection

720N-480N=240N

therefore work done = force*displacement

=240*12

=2880J.

so,total work done =2880J

Answer 2

Answer:

The work done by the person is 2880J.

Explanation:

The work done on the refrigerator is given as,

$W=F.s$      (1)

Where,

W=work done on the refrigerator

F=the net force acting on the refrigerator

s=distance through which the refrigerator is displaced

From the question we have,

Weight of the refrigerator(w)=720N

Distance through which the refrigerator is displaced=12m

Force of friction between the refrigerator and the floor(f)=480N

Since the force of friction acts opposite to the direction of displacement then the net force will be,

$F=720N-480N=240N$       (2)

By substituting the required values in equation (1) we get;

$W=240\times 12=2880J$

Hence, the work done by the person is 2880J.