Rolling Friction

Q.

Is rolling friction greater than sliding friction?

Q. Why are machines oiled from time to time?

Q.

Definition of rolling friction.

Q.

Differentiate between sliding friction and rolling friction?

Q.

Is there a force of friction between the wheels of a moving train and iron rails? If yes, name the type of friction. If an air cushion can be introduced between the wheel and the rail, what effect will it have on the friction?

Q.

_________friction is acting between wheels of a running vehicle and ground.

1. none of these

2. rolling

3. sliding

4. static

Q.

Define Rolling friction.

Q.

For the same pair of bodies, the correct relation between different types of friction is:

1. Static friction > sliding friction > rolling friction.

2. Sliding friction > rolling friction > static friction.

3. Static friction > rolling friction > sliding friction.
4. Sliding friction > static friction > rolling friction.

Q.

Question 2

Four children were asked to arrange forces due to rolling, static and sliding frictions in a decreasing order. Their arrangements are given below. Choose the correct arrangement explaining why.
1st boy - rolling, static, sliding
2nd boy - rolling, sliding, static
3rd boy - static, sliding, rolling
4th boy - sliding, static, rolling

Q.

It is convenient to pull the luggage fitted with roller, why?

Q. If a book is placed on the table at rest, does friction act on it?

Q. Which of the following is the correct order of various types of friction?

1. Limiting friction > Sliding friction > Rolling friction
2. Sliding friction > Rolling friction > Limiting friction
3. Rolling friction > Sliding friction > Static friction
4. Rolling friction > Static friction > Sliding friction

Q.

Wheels are added to a trolley for smooth travel. What is the principle behind this?

1. There is no comparison between sliding friction and rolling friction.

2. Rolling friction is less than sliding friction.

3. Both sliding friction and rolling friction are the same

4. Sliding friction is less than rolling friction

Q. Why is having treads on tyres undesirable for racing cars (like the Formula1 cars)?

1. Treads increase friction and hence tyres start skidding
2. Tyres cannot take advantage of the plowing effect on hard roads if they have treads and hence friction will reduce
3. Friction would reduce because treads would make F1 tyres smaller
4. None of the above

Q. parachute is invariably used while jumping from aeroplane. answer in one word

Q. WRITE THE UNIT OF COEFFICIENT OF KINETIC AND ROLLING FRICTION?

Q. Is there a force of friction in space

Q. A football kicked by a girl stops after moving for some distance. This is due to:

1. Gravity
2. Friction
3. Magnetism
4. Normal force