Physics ICSE Class 6 Important Questions Chapter 4 Friction
Practice Questions
Question 1.
Name two factors that influence the magnitude of friction.
Answer:
- The roughness of the surfaces in contact.
- The weight of the object.
Question 2.
Why do we have to apply more force to push a heavy box than to push a lighter one ?
Answer:
The norma force exerted by the ground on a body resting on it is equal to the gravitational force on the earth acting on the friction depends on the weight of the object. body, or the weight of the body. So the normal force exerted on a heavier body is more than that exerted on a lighter body. Greater the normal force experienced by a body, greater is its frictional force. So, a greater force is required to move a heavier body than a lighter body.
Question 3.
What are two types of friction ?
Answer:
(i) Static friction – It is the force of friction acting between two bodies in contact while at rest
(ii) Kinetic friction – It is the force of friction acting between two bodies in contact while in motion.
It is two types –
(a) Sliding friction
(b) Rolling friction
Question 4.
Fill in the blanks.
1. Rough surfaced offer ………….. degree of friction compared to smooth surfaces.
Answer:
Rough surfaces offer greater degree of friction compared to smooth surfaces.
2. The force of friction is very large when both the surfaces in contact are …………..
Answer:
The force of friction is very large when both the surfaces in contact are rough.
3. Normal force exerted on a heavier body is ………….. than that exerted on a lighter body.
Answer:
Normal force exerted on a heavier body is more than that exerted on a lighter body.
4. The static friction is ………… when the applied force is just short of the force required to start motion between the two bodies in contact.
Answer:
The static friction is maximum when the applied force is just short of the force required to start motion between the two bodies in contact.
5. When we slide an object on a’ surface, the friction produced between the object and the surface is called ………… friction.
Answer:
When we slide an object on a surface, the friction produced between the object and the surface is called sliding friction.
6. When we apply brakes, the force of between the brake shoe and the rim of the wheel allows us to stop a bicycle or a moving vehicle.
Answer:
When we apply brakes, the force of friction between the brake shoe and the rim of the wheel allows us to stop a bicycle or a moving vehicle.
7. The simplest way to increase friction between moving surfaces is to make them ………..
Answer:
The simplest way to increase friction between moving surface is to make them rough.
8. Sand or gravel are often spread on slippery ground to ………….. friction.
Answer:
Sand on gravel are often spread on slipper)’ ground to increase friction.
9. …………. is used in reducing friction between parts of machines which get overheated while working.
Answer:
Graphite is used in reducing friction between parts of machines which get overheated while working.
10. The friction caused due to fluids (liquids and gases) IN termed as ……………
Answer:
The friction caused due to fluids (liquids and gases) is termed as drag.
ICSE Class 6 Physics Important Questions