Merits and Demerits of Friction
Trending Questions
- Frictional force
- Gravitational force
- Magnetic force
- Muscular force
Kinetic theory of matter states that molecules are in constant motion and posses kinetic energy. But where did these molecules get the energy from?
- North
- South
- East
- West
- kinetic
- chemical
- potential
When we rub our hands vigorously our hands get hot .Why ?
Which of the following options illustrate the advantageous effects of friction?
Wear and tear of shoes
Walking
Writing on blackboard with a chalk
Fixing a nail to wall
When brakes are applied, from where does the extra friction come into play to stop the bicycle? [2 MARKS]
Why does a knife become blunt with use?
- Walking on road
- Riding bicycle
- pulling suitcase
- writing on paper with pen
Why does a body rolling on the surface of the Earth come to the state of rest after some time?
it has mass
it experiences friction
it has inertia of rest.
All of the above
Identify in which of the following cases friction plays a helpful role.
Lighting a matchstick
Writing on a blackboard with a chalk
Wearing of shoes
Heating of machinery
On cooling down a substance, there is a loss of heat and their kinetic energy ___________.
- east
- south
- west
- north
What would happen if there is no friction in life?
- roughness
- plowing effect
- adhesion
How friction enables us to walk without slipping?
What are the disadvantages of friction?
- bicycle produces extra energy which helps us to reach our destination in less time.
- the shape of the bicycle minimizes the air drag which helps to move forward easily.
- riding with bicycle increases the normal force which increases static friction. Which helps us to move forward easily.
- rolling friction, acted on bicycle's wheels, minimizes our efforts.
(i) shape of the object
(ii) mass of the object
Choose the correct one.
- Only (i) is correct
- Only (ii) is correct
- Both (i) and (ii) are correct
- None of (i) and (ii) are correct
Which of the following is a lubricant?
Rubber
Sand
Salt
Grease
Friction is good or bad for us ? Why?
Friction is a necessary evil.
- Holding things
- Heat generation
- Wear and tear
Wheels are added to trolleys for smooth travel. What is the principle behind this?
Sliding friction is less than rolling friction.
Rolling friction is less than sliding friction.
- Rolling friction is less than static friction.
- Static friction is less than rolling friction.