Science

Friction

Question:

Iqbal has to push a lighter box and Seema has to push a similar heavier box on the same floor. Who will have to apply a larger force and why?

Answer:

Force of friction arises because of interlocking of irregularities on the two surfaces in contact. When a heavy object is placed on the floor, the interlocking of irregularities on the urfaces of box and floor become strong. This is because the two surfaces in contact are pressed harder. Hence, more force is required to overcome the interlocking. Thus, to push the heavier box, Seema has to apply a greater force than Iqbal.
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Questions and Answers

Friction

Q 1.

static, sliding, rolling
Answer

Q 2.

wet marble floor, dry marble floor, newspaper and towel
Answer

Q 3.

Suppose your writing desk is tilted a little. A book kept on it starts sliding down. Show the direction of frictional force acting on it.
Answer

Q 4.

Explain why sliding friction is less than static friction.
Answer

Q 5.

Iqbal has to push a lighter box and Seema has to push a similar heavier box on the same floor. Who will have to apply a larger force and why?
Answer

Q 6.

Give examples to show that friction is both a friend and a foe.
Answer

Q 7.

You spill a bucket of soapy water on a marble floor accidentally. Would it make it easier or more difficult for you to walk on the floor? Why?
Answer

Q 8.

Explain why objects moving in fluids must have special shapes.
Answer

Q 9.

Explain why sportsmen use shoes with spikes.
Answer