Question

1. When a pencil cell is released from a certain point on
an inclined wooden board, it travels a distance of 35
cm on floor A before it comes to rest. When the same
pencil cell is released from the same point on the
same inclined board, it travels a distance of 20 cm on
floor B before coming to rest. Which floor, A or B,
offers greater friction? Give reason for your answer.
2. What kind of friction comes into play:
(a) When a block of wood kept on table moves slowly?
(b) When a block of wood kept on table just tends to move
( or slip)
(c) When a block of wood kept on cylindrical iron rods
moves?
3. Out of sliding friction, static friction & rolling friction:
Which one is the Smaller and largest?
3. Explain why, sliding friction is less than static friction.
4. What is meant by ‘rolling friction’?
5. Why does a man slip when he steps on a banana peel
thrown on the road?
6. Explain why:
(a) a pencil will write on paper but not on glass
(b) The handles of motor cycle are covered with a rubber
sheet with spikes
© The soles of our shoes wear out gradually.
(d) Tyres of cars wear out gradually.
( e) Why does a matchstick light when we strike it on a
rough surface?

Answer 1

Explanation:

Veeeeryy lengthy question