Question

With the help of an activity, explain the effect of friction on the nature of surface in contact

Answer 1

Explanation:

Aim-To demonstrate that friction depend on the nature of surfaces in contact

Materials required- Sheet of cardboard, plastic sheet, dand paper, and toy car

Procedure

1 Take sheet of cardboard and divide it into two

parts.

2 Paste a plastic sheet on one part and sand paper on other part of the cardboard.

3 Now move a toy car on each of the surfaces and record the distance moved by the car with the help of a ruler.

Observation- You will notice that the toy car moves the greater distance on the plastic sheet rather than the sand paper.

Conclusion- Out of both the surfaces, the surface of the sand paper is rough and that the plastic is smooth. Thus, more friction is created on the sand paper, which doesn't allow the toy car to cover more distance.

Answer 2

Answer:You will need a brick, a hook, a string and a spring balance

1. Tie a string around a brick and attach a hook to it. Take a spring balance and attach

it to the hook.

2. Place the arrangement horizontally

as shown in figure on a smooth

surface.

3. Gently pull the spring balance. Keep on increasing the force on the

spring

till the brick just starts to move. Note the reading on the spring balance at that

moment when the brick moves. It represents the force of friction between the brick

and the smooth surface.

4. Take the same arrangement to a rough surface and repeat step 3. Again note the

reading on the spring balance.

You have to apply a larger force on the brick which is placed on the rough surface as

compared to the smooth surface to move the brick. The spring balance shows greater

reading on the rough surface than that on the smooth surface.

This shows that rough surfaces offer greater friction than smooth surfaces

Explanation: