Name: Effects of Friction
Uploaded: 2019-07-19
Duration: 4 min 2 s
Description: We all know that a kind of opposing force comes into play when two surfaces rub against each other. What is this force called, and what is its cause? Let’s f...

Question

Rolling friction is less than static friction and sliding friction. Explain with the help of an activity.

Accepted Answer

The friction that exists between two objects which are at rest relative to each other is known as static friction. The friction acting on a body when it is sliding over a surface is called sliding friction. When an object (like a wheel) rolls over the surface of another object, the resistance to its motion is called rolling friction. In order to show that rolling friction is less than static friction and sliding friction we require three bottle caps of different sizes, marbles, and a heavy object. First we have to mark the smallest cap as $1$ , the larger cap as $2$ , and the largest cap as $3$ . Put the inverted cap $1$ inside cap $2$ and then put the inverted cap $3$ on top of cap $2$ . Put the heavy object on top of cap $3$ and try to rotate the object by giving it a push. We can see that the heavy object does not move easily and smoothly. Now, remove cap $3$ and fill the space between caps $1$ and $2$ with marbles. Put cap $3$ in such a way that it sits on the marbles without touching the other caps. Again, put the heavy object over cap $3$ and try to rotate it. We can see that the object rotates easily and smoothly in this case.

In the first case, the static friction between the three caps prevented them from moving. This made the movement of the heavy object difficult. In the second case, the static friction between the caps was changed into rolling friction by filling the gaps with marbles. Rolling friction is much smaller than static or sliding friction. So, the application of even a small force will make the heavy object move easily.

Rolling friction is less than static friction and sliding friction. Explain with the help of an activity.

Important Questions on Friction

Learn and Prepare for any exam you want !