Science

Friction

Question:

Explain why objects moving in fluids must have special shapes.

Answer:

When a body moves through a fluid, it experiences an opposing force which tries to oppose its motion through the fluid. This opposing force is known as the drag force. This frictional force depends on the shape of the body. By giving objects a special shape, the force of friction acting on it can be minimised. Hence, it becomes easier for the body to move through the fluid.
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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