Question

A person used the force shown in the figure to move a load with constant velocity on a given surface to identify the correct surface profiles.

A)

B)

C)

D) None of the above

Answer 1

Hint: In this question we have to find the surface through which the person can move the load with constant velocity. We will do this question with the help of a given figure. We will divide the given distance L in two parts and then we will see how force is getting affected by distance and we will try to find out the correct surface.

Complete solution:
As we can see that force is being applied by the person to move a load with constant velocity. We can divide the distance in two parts 0 to x and x to L.
As we can see in the diagram that from 0 to x the force is positive constant and from x to L force is negative constant.
So, it can be seen that in option (A) the surface is first increasing then it is decreasing.
In option (B) the surface is constant then it is decreasing.
In option (C) the surface is increasing then it becomes constant.
In option (D) the surface is curved.
Result- So, from the above explanation we can see that option (A) is correct because in this the surface is first increasing and then it is decreasing.

Note: In this question we have used the concept of positive and negative constants. This is the concept in which we decide which one is positive constant and which one is negative according to the given diagram. In this question it is easy to identify the positive and negative constants because it is quite an easy diagram. In some questions we might get a bit of a different and difficult situation. In that situation we should be careful while finding the positive and negative parts.