Question

Why are wheels of cars, buses etc. are made circular?
(A) to minimize friction
(B) too add more electrostatic force
(C) no particular reason
(D) circle looks better

Answer 1

This question uses the concept of friction, so you need to apply it accordingly. Further, rolling and sliding friction can also be used to explain the answer more accurately. As we know that the friction is a type of resisting force that tries to slow down the speed of a moving body. This would help you to figure out the correct answer from the options.

Complete step by step answer:
As we know that friction is a necessary evil that helps us to perform many activities like allows us to walk or helps us to write and many more. Surface and the shape of the object plays an important role in increasing or decreasing the friction. When a system is in motion, two different principle types of friction act on it that is sliding and rolling friction. Rolling friction is always smaller than sliding friction. This is the reason, the wheels of automobiles are made circular in shape. When the wheels move by revolving or roiling on the surface, rolling friction acts on it. This shape helps to reduce or to minimize the friction. This is also because the area of contact in case of rolling friction is less as compared to sliding friction. Moreover, if the wheels are made of any other shape, like hexagon or square, then the sliding friction would come into action. This would have caused more friction and resistance to automobiles. Further, the motion of the vehicle would not be smooth and comfortable as it is in the case of circular wheels.

So, the correct answer is “Option A”.

Note:
Even though you are not sure about the answer conceptually, you can figure out the correct option by looking at the options. You know that there is no role of electrostatic force in the wheel, and the last two options cannot be the answer. So, the first option would be the answer.