If the work done by a body on application of a constant force is directly proportional to the distance travelled by the body, express this in the form of an equation in two variables and draw the graph of the same by taking the constant force as 5 units. Also read from the graph the work done when the distance travelled by the body is:

**(i)** 2 units ** (ii)** 0 unit

**Solution:**

It is given that work done by a body on application of a constant force is directly proportional to the distance travelled by the body.

So, we have where W is the work done and S is the distance travelled by the body.

where k is the constant force. ** (1)**

It is equation consisting of two variables W and S. k is just a constant here.

We will draw graph of this equation taking units. Putting in **(1), **we get

To draw graph of , we will find 3 or 4 set of solutions.

Putting in the equation , we get

Therefore, is one of the infinite possible solutions.

Similarly, putting in the equation , we get

Therefore, is one of the infinite possible solutions.

Putting in the equation , we get

Therefore, is one of the infinite possible solutions.

Therefore, three different solutions for equation are:

Now, we plot all these three points on the Cartesian plane. When we join these points, it makes a straight line.

**(i)** We can read from the graph that when units, we have units

**(ii)** Similarly, when units, we have units.