1. (a) Friction of _____________________ between surfaces in contact with each other.
(b) Friction depends on the ________________ of the surface.
(c) Friction produces __________.
(d) Sprinkle the powder on the cardboard and ________ rub it.
(e) Sliding friction is __________ compared to static friction
1. (a) Friction of _____________________ between surfaces in contact with each other.
(b) Friction depends on the ________________ of the surface.(c) Friction produces __________.
(d) Sprinkle the powder on the cardboard and ________ rub it.
(e) Sliding friction is __________ compared to static friction
Explanation:
(A) Friction prevents movement between contacting surfaces.
(B) Type of surface affects friction.
(C) Heat is generated by friction.
(D) Sprinkle powder on cardboard to reduce friction.
(E) Sliding friction is lower than static friction.
2. Ask four children to rank rolling friction, static friction, and sliding friction in descending order. Their layout is as follows.
Choose the right layout.
(a) rolling, static, slippery
(b) rolling, slippery, static
(c) static, slippery, rolling
(d) slippery, static, rolling
2. Ask four children to rank rolling friction, static friction, and sliding friction in descending order. Their layout is as follows.
Choose the right layout.
(a) rolling, static, slippery
(b) rolling, slippery, static
(c) static, slippery, rolling
(d) slippery, static, rolling
Explanation:
The answer is static, slippery,
rolling.
3. Alida is driving her toy car on a dry marble floor, a wet marble floor with newspapers and towels on the floor. The frictional forces acting on the different surfaces of the car are in increasing order
(a) wet marble floor, dry marble floor, newspaper and towel
(b) newspaper, towel, dry marble floor, floor wet marble floors
( c) Towels, newspapers, dry marble floors, wet marble floors
(d) wet marble floors, dry marble floors, towels, newspapers
3. Alida is driving her toy car on a dry marble floor, a wet marble floor with newspapers and towels on the floor. The frictional forces acting on the different surfaces of the car are in increasing order
(a) wet marble floor, dry marble floor, newspaper and towel
(b) newspaper, towel, dry marble floor, floor wet marble floors
( c) Towels, newspapers, dry marble floors, wet marble floors
(d) wet marble floors, dry marble floors, towels, newspapers
Explanation:
The answer is (a) marble floors wet, dry marble floors, newspapers and towels.
4. Let's say your desk is slightly tilted. A book held on it began to slip. Show
4. Let's say your desk is slightly tilted. A book held on it began to slip. Show
Explanation:
When a book slides off a table, friction is created between the book and the table. The book experiences an upward frictional force against the direction in which it is moving. The figure below illustrates this.
5. You accidentally spill a bucket of soapy water on the marble floor. Will it make it easier or harder for you to walk on the ground? For what?
5. You accidentally spill a bucket of soapy water on the marble floor. Will it make it easier or harder for you to walk on the ground? For what?
Explanation:
The friction that exists between our feet and the earth makes us walk on it.
When we walk, we use our feet to push the ground. The reason we can walk is because of the friction pushing it forward. When soapy water is spilled on the floor, there is less friction between the floor and your feet. Therefore, it is difficult to walk on soapy floors.
6. Explain why athletes wear spikes.
6. Explain why athletes wear spikes.
Explanation:
Spikes are used by athletes as they provide excellent traction while running. Indeed,the studs increase the friction between the shoe and the ground.
7. Iqbal has to push a lighter box and Seema has to push a similar heavier box to the same floor.Who will need to exert more force and why?
7. Iqbal has to push a lighter box and Seema has to push a similar heavier box to the same floor.Who will need to exert more force and why?
Explanation:
Friction is caused by imperfections on two surfaces that touch and interlock. When a heavy object is placed on the floor, the surface imperfections of the box and the floor begin to fit together tightly. This is due to the increased pressure between the two surfaces. Therefore, more force is needed to break the lock.
Seema must therefore use more force than Iqbal to push the heavier box.
8. Explain why sliding friction is less than static friction.
8. Explain why sliding friction is less than static friction.
Explanation:
When two things come into contact, the flaws on their surfaces stick together, forming friction. Chained working hours are rarely permitted.
As a result, the fitting is insufficient. Because of this interlock, less force is needed to break it through. Therefore, sliding friction is less than static friction.
9. Give an example of how friction is both friend and foe.
9. Give an example of how friction is both friend and foe.
Explanation:
Benefits of Friction
a) We can walk because of friction.
b) The friction created between the tip of the pen and the paper allows us to write.
Disadvantages of friction
a) Tires and shoe soles age over time due to friction.
b) Heat is generated by friction between the different parts of the machine. This could damage the device.
10. Explain why objects moving in liquids must have particular shapes.
10. Explain why objects moving in liquids must have particular shapes.
Explanation:
As the body moves through the fluid, it encounters a counterforce that tries to stop it. The reaction force affected by the shape of the body is friction. Drag force is what it is called.
The shape of an object can be changed to reduce the frictional force exerted on it. Therefore, it becomes easier to move the body through the liquid.
Also Read: Ch - 12 Friction Extra Questions
