Question

C. Mention one method which can used to reduce friction in fo
1. To reduce friction in wheels of cars.
2. To reduce squeaking sound in door.
3. To reduce friction in heat producing grinding machines.
4. To change rough surface into smooth surface.
5. To reduce fluid friction in objects.
D. Answer the following question.
1. On what principle do ball bearings work?
2. Why do sportsmen use shoes with spikes?​

Answer 1

Explanation:

1.having less groves and ridges in wheels can help in reducing friction

2.by oiling the hinges of doors

D.2.they use shoes with spikes because they need more grip in the field while running cuz the spikes get into the soil and provide more grip