All Exams >
Class 8 >
Science Olympiad Class 8 >
All Questions
All questions of Friction for Class 8 Exam
What type of friction does not allow two surfaces to slide upon one another?
- a)fluid friction
- b)static friction
- c)sliding friction
- d)drag
Correct answer is option 'B'. Can you explain this answer?
What type of friction does not allow two surfaces to slide upon one another?
a)
fluid friction
b)
static friction
c)
sliding friction
d)
drag
|
Mannat Thukral answered |
Yes static friction is the only type of friction which does not allow two objects to slide past one another as this friction is required at the beginning to overcome the friction on the object due to which it will start moving and then sliding friction would be required to maintain the doped of the object.thus,sliding friction is smaller than static friction.
Which of these statements is NOT correct?- a)A ball moving on a horizontal surface stops due to force of friction.
- b)Force of friction helps us to walk on ground.
- c)Wheels are spherical in shape as rolling friction is less than sliding friction.
- d)Tyres have grooves to reduce the friction.
Correct answer is option 'D'. Can you explain this answer?
Which of these statements is NOT correct?
a)
A ball moving on a horizontal surface stops due to force of friction.
b)
Force of friction helps us to walk on ground.
c)
Wheels are spherical in shape as rolling friction is less than sliding friction.
d)
Tyres have grooves to reduce the friction.
|
Phone Kyt answered |
55349
Which of these is true about friction?
- a)It can make a moving object faster.
- b)It can not change the direction of a moving object.
- c)It can stop a moving object.
- d)It can change the shape of an object.
Correct answer is option 'C'. Can you explain this answer?
Which of these is true about friction?
a)
It can make a moving object faster.
b)
It can not change the direction of a moving object.
c)
It can stop a moving object.
d)
It can change the shape of an object.
|
Poulomi Yadav answered |
The correct answer is c
Friction can slow things down and stop them
The force of friction between two bodies in contact is- a)parallel to body position
- b)parallel to contact surface
- c)perpendicular to contact surface
- d)inclined at 450 to contact surface
Correct answer is option 'B'. Can you explain this answer?
The force of friction between two bodies in contact is
a)
parallel to body position
b)
parallel to contact surface
c)
perpendicular to contact surface
d)
inclined at 450 to contact surface
|
Abhiraj Harsh answered |
Example when we walk,our feet is parallel to the road. so option b is correct.
Which of these frictions is the least in magnitude?- a)static friction
- b)sliding friction
- c)rolling friction
- d)all are equal
Correct answer is option 'C'. Can you explain this answer?
Which of these frictions is the least in magnitude?
a)
static friction
b)
sliding friction
c)
rolling friction
d)
all are equal
|
|
Lalith Togalla answered |
The answer is option C because when you roll you push you self and there would also be less magnitude because only some of your body parts would touch the ground to cause a small amount of fiction.
please upvote to me and my answer and also start following me!!!!!
please upvote to me and my answer and also start following me!!!!!
The bodies of aeroplanes, missiles, rockets, cars are streamlined to reduce friction with air. This friction forces is called
- a)air resistance
- b)air pull
- c)drag
- d)gravitational resistance
Correct answer is option 'A'. Can you explain this answer?
The bodies of aeroplanes, missiles, rockets, cars are streamlined to reduce friction with air. This friction forces is called
a)
air resistance
b)
air pull
c)
drag
d)
gravitational resistance
|
Pooja Shah answered |
The bodies of aeroplanes, missiles, rockets, cars are streamlined to reduce friction with air. This friction forces is called air resistance.
Method of increasing friction is by- a)using lubricant
- b)providing grooves on sole of shoes
- c)polishing the surfaces
- d)using ball bearing
Correct answer is option 'B'. Can you explain this answer?
Method of increasing friction is by
a)
using lubricant
b)
providing grooves on sole of shoes
c)
polishing the surfaces
d)
using ball bearing
|
Abhay Kulkarni answered |
Increasing friction by providing grooves on the sole of shoes:
Friction is the force that resists the relative motion of two surfaces in contact. It is responsible for the grip between objects and helps prevent slipping or sliding. There are several methods to increase friction, and one effective way is by providing grooves on the sole of shoes. This method is commonly used in the design of various types of footwear, especially those intended for activities that require good traction, such as sports shoes, hiking boots, and work boots.
1. Explanation of grooves on the sole of shoes:
- Grooves are shallow channels or indentations on the surface of the shoe sole.
- These grooves increase the surface area of contact between the shoe and the ground.
- The irregularities created by the grooves help to create interlocking points with the ground, enhancing traction.
- The grooves also act as channels for water, mud, or other debris to escape, preventing the accumulation of slippery substances.
2. Increased contact area:
- The grooves on the sole of shoes increase the contact area between the shoe and the ground.
- With a larger contact area, the force of friction is distributed over a broader surface, resulting in a stronger grip.
- This is particularly important when walking or running on uneven or slippery surfaces.
3. Interlocking points:
- The grooves create irregularities on the shoe sole, which can interlock with microscopic irregularities on the ground surface.
- This interlocking mechanism enhances the grip between the shoe and the ground, increasing friction.
4. Water and debris dispersion:
- The grooves on the sole of shoes act as channels for water, mud, or other debris to escape.
- By allowing these substances to flow out of the grooves, the shoe maintains a better grip on the ground.
- Without grooves, the shoe sole could become a slippery surface due to the accumulation of water or debris, reducing friction.
In conclusion, providing grooves on the sole of shoes is an effective method of increasing friction. The grooves increase the contact area, create interlocking points, and help disperse water and debris. These factors contribute to a stronger grip and better traction, reducing the likelihood of slipping or sliding.
Friction is the force that resists the relative motion of two surfaces in contact. It is responsible for the grip between objects and helps prevent slipping or sliding. There are several methods to increase friction, and one effective way is by providing grooves on the sole of shoes. This method is commonly used in the design of various types of footwear, especially those intended for activities that require good traction, such as sports shoes, hiking boots, and work boots.
1. Explanation of grooves on the sole of shoes:
- Grooves are shallow channels or indentations on the surface of the shoe sole.
- These grooves increase the surface area of contact between the shoe and the ground.
- The irregularities created by the grooves help to create interlocking points with the ground, enhancing traction.
- The grooves also act as channels for water, mud, or other debris to escape, preventing the accumulation of slippery substances.
2. Increased contact area:
- The grooves on the sole of shoes increase the contact area between the shoe and the ground.
- With a larger contact area, the force of friction is distributed over a broader surface, resulting in a stronger grip.
- This is particularly important when walking or running on uneven or slippery surfaces.
3. Interlocking points:
- The grooves create irregularities on the shoe sole, which can interlock with microscopic irregularities on the ground surface.
- This interlocking mechanism enhances the grip between the shoe and the ground, increasing friction.
4. Water and debris dispersion:
- The grooves on the sole of shoes act as channels for water, mud, or other debris to escape.
- By allowing these substances to flow out of the grooves, the shoe maintains a better grip on the ground.
- Without grooves, the shoe sole could become a slippery surface due to the accumulation of water or debris, reducing friction.
In conclusion, providing grooves on the sole of shoes is an effective method of increasing friction. The grooves increase the contact area, create interlocking points, and help disperse water and debris. These factors contribute to a stronger grip and better traction, reducing the likelihood of slipping or sliding.
Friction due to water and air can be reduced by suitably designing the shape of the objects. This is called- a)ball - setting
- b)frictional adjustment
- c)streamlining
- d)figure correction
Correct answer is option 'C'. Can you explain this answer?
Friction due to water and air can be reduced by suitably designing the shape of the objects. This is called
a)
ball - setting
b)
frictional adjustment
c)
streamlining
d)
figure correction
|
Devanshi Basu answered |
Streamlining
One way to reduce friction due to water and air is by suitably designing the shape of the objects to minimize resistance. This process is known as streamlining.
Why Streamlining is Important
- Streamlining helps reduce drag force which is the resistance encountered when an object moves through a fluid (water or air).
- By reducing drag force, streamlining allows objects to move more efficiently and with less energy consumption.
Designing Streamlined Shapes
- Streamlined shapes are typically long and tapered, with smooth curves that allow fluids to flow easily around the object.
- Objects with streamlined shapes are often pointed at the front and gradually taper towards the back, reducing turbulence and resistance.
Examples of Streamlining
- Aircraft are designed with streamlined shapes to reduce air resistance during flight.
- Fish have streamlined bodies that allow them to move through water with minimal resistance.
- Cars are also designed with aerodynamic shapes to reduce drag and improve fuel efficiency.
Conclusion
In conclusion, streamlining is a vital concept in reducing friction due to water and air by designing objects with shapes that minimize resistance. By incorporating streamlining principles, engineers can create more efficient and effective designs for various applications.
The force of friction that exists between the surfaces in contact when one body slides over the surface of other body is called ____ friction.- a)rolling
- b)static
- c)sliding
- d)moving
Correct answer is option 'C'. Can you explain this answer?
The force of friction that exists between the surfaces in contact when one body slides over the surface of other body is called ____ friction.
a)
rolling
b)
static
c)
sliding
d)
moving
|
Neha Shi answered |
Sliding friction - the object slides over the other
Which of the following is correct regarding friction?- a)wastes energy
- b)wears out the rubbing surface
- c)generates heat
- d)all of these
Correct answer is option 'D'. Can you explain this answer?
Which of the following is correct regarding friction?
a)
wastes energy
b)
wears out the rubbing surface
c)
generates heat
d)
all of these
|
|
Maya Rane answered |
Friction is the force that opposes motion when two surfaces come in contact with each other. The correct option regarding friction is 'D', all of the above. Friction has several effects, some of which are:
Wastes Energy:
Friction causes a loss of energy in the form of heat. When two surfaces rub against each other, the energy of motion is converted into heat energy. This heat energy is dissipated into the environment and cannot be used for any useful work.
Wears Out the Rubbing Surface:
Friction causes wear and tear of the rubbing surfaces. When two surfaces rub against each other, they experience a certain amount of wear and tear due to the constant friction. Over a period of time, this wear and tear can cause damage to the rubbing surfaces and reduce their effectiveness.
Generates Heat:
Friction generates heat due to the conversion of mechanical energy into heat energy. The amount of heat generated depends on the nature of the surfaces in contact and the force with which they are rubbing against each other. This heat can be useful in some applications, but in most cases, it is wasted energy.
In conclusion, friction has several effects, including wasting energy, wearing out the rubbing surfaces, and generating heat. These effects can be both useful and harmful, depending on the situation. However, it is important to understand the nature of friction and its effects in order to minimize its negative impacts and maximize its positive ones.
Wastes Energy:
Friction causes a loss of energy in the form of heat. When two surfaces rub against each other, the energy of motion is converted into heat energy. This heat energy is dissipated into the environment and cannot be used for any useful work.
Wears Out the Rubbing Surface:
Friction causes wear and tear of the rubbing surfaces. When two surfaces rub against each other, they experience a certain amount of wear and tear due to the constant friction. Over a period of time, this wear and tear can cause damage to the rubbing surfaces and reduce their effectiveness.
Generates Heat:
Friction generates heat due to the conversion of mechanical energy into heat energy. The amount of heat generated depends on the nature of the surfaces in contact and the force with which they are rubbing against each other. This heat can be useful in some applications, but in most cases, it is wasted energy.
In conclusion, friction has several effects, including wasting energy, wearing out the rubbing surfaces, and generating heat. These effects can be both useful and harmful, depending on the situation. However, it is important to understand the nature of friction and its effects in order to minimize its negative impacts and maximize its positive ones.
Friction is minimized by- a)polishing and lubrication
- b)streamlining
- c)use of wheels and ball bearings
- d)all of these
Correct answer is option 'D'. Can you explain this answer?
Friction is minimized by
a)
polishing and lubrication
b)
streamlining
c)
use of wheels and ball bearings
d)
all of these
|
Aditi Saxena answered |
Option (d) all of these is correct answer.
Friction is a force that resists the relative motion or tendency of objects to slide or roll along a surface. It can be minimized by various methods such as polishing and lubrication, streamlining, and the use of wheels and ball bearings.
Polishing and lubrication involve smoothing and coating the surfaces of objects in order to reduce the roughness and increase the smoothness of their contact, which can help to reduce the amount of friction between them.
Streamlining refers to the design of objects to reduce drag or resistance to motion through a fluid, such as air or water. Streamlining can help to minimize friction by reducing the amount of resistance that an object encounters as it moves through a fluid.
The use of wheels and ball bearings allows objects to roll rather than slide, which can significantly reduce the amount of friction involved in their movement. Ball bearings in particular allow objects to rotate smoothly and with minimal resistance, making them ideal for use in a wide range of applications where reduced friction is desired.
Chapter doubts & questions for Friction - Science Olympiad Class 8 2025 is part of Class 8 exam preparation. The chapters have been prepared according to the Class 8 exam syllabus. The Chapter doubts & questions, notes, tests & MCQs are made for Class 8 2025 Exam. Find important definitions, questions, notes, meanings, examples, exercises, MCQs and online tests here.
Chapter doubts & questions of Friction - Science Olympiad Class 8 in English & Hindi are available as part of Class 8 exam.
Download more important topics, notes, lectures and mock test series for Class 8 Exam by signing up for free.
Science Olympiad Class 8
70 videos|132 docs|67 tests
|
|
© EduRev
|
Education Revolution
|
|
Signup to see your scores
go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup