3.
is the frictional force experienced by an object sering
4. A ball will experience
friction than a rectangular tile
Answers
hey, what you want to ask
Step-by-step explanation:
QUESTIONS FROM TEXTBOOK
Q.1. Fill in the blanks:
(a) Friction opposes the ______ between the surfaces in contact with each other.
(b) Friction depends on the ______ of surfaces.
(c) Friction produces ______.
(d) Sprinkling of powder on the carrom board ______ friction.
(e) Sliding friction is ______ than the static friction.
Ans. (a) relative motion (b) nature (c) heat
(d) reduces (e) less.
Q.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:
(a) rolling, static, sliding
(b) rolling, sliding, static
(c) static, sliding, rolling
(d) sliding, static, rolling
Ans. (c) Static, sliding, rolling.
Q.3. Alida runs her toy car on a dry marble floor, wet marble floor, newspaper and towel spread on the floor. The force of friction acting on the car on different surfaces in increasing order will be
(a) wet marble floor, dry marble floor, newspaper, towel.
(b) newspaper, towel, dry marble floor, wet marble floor.
(c) towel, newspaper, dry marble floor, wet marble floor.
(d) wet marble floor, dry marble floor, towel, newspaper.
Ans. (a) wet marble floor, dry marble floor, newspaper, towel.
Q.4. 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.
Ans. The book moves downwards. The frictional force is acting opposite to the movement of book. So it acts upwards.
Q.5. You spill a bucket of soapy water on a marble floor accidently. Would it make it easier or more difficult for you on the floor? Why?
Ans. The layer of soap makes floor smooth due to which the friction is reduced and the foot cannot make a proper grip on the floor. Therefore it is difficult to walk on a soapy floor and we start to slip on the floor.
Q.6. Explain why sportsmen use shoes with spikes.
Ans. Sportsmen use shoes with spike to increase the friction between shoes and the surface. The shoes with spike do not slip while they run or play.
Q.7. 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?
Ans. The heavy object will be pressed hard against the opposite surface and produces more friction. So Seema will have to apply a larger force due to more friction.
Q.8. Explain why sliding friction is less than static friction.
Ans. The two sliding objects find less time to get interlocked against each other (objects and irregularities of surface). So they get less friction. Therefore sliding friction is always less than static friction.
Q.9. Give examples to show that friction is both a friend and a foe.
Ans. Examples to show that friction is a friend and a foe: