Physics · Science General

Newtonian Mechanics and Forces

1,605 Questions

Newtonian mechanics studies the motion of objects and the physical laws governing them. This hub covers friction, gravitational force, inertia, and vector quantities. Mastering these fundamental physics concepts is essential for various government competitive exams.

Laws of motionFriction and inertiaVector and scalar quantitiesGravitational accelerationArchimedes principle

Newtonian Mechanics and Forces Questions

Multiple choice

Effective control requires

  1. flexibility

  2. rigidity

  3. high cost

  4. none of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Controls are not an end in themselves. In order to accomplish objectives if it becomes necessary to revise the plans, the control system must have the attribute to adapt itself to new developments. Control must be flexible in the sense that it should respond favourably to the conditions.

Multiple choice

In which direction does force of friction act?

  1. Upward direction

  2. Downward direction

  3. The direction opposite to motion

  4. The direction of motion
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Friction opposes the relative motion between the two surfaces in contact, i.e. force of friction always acts in the direction opposite to the motion.

Multiple choice

It is difficult to drag a bucket full of water than an empty bucket because

  1. force of friction decreases as we drag a bucket full of water

  2. force of friction increases with the increase of normal force due to increased weight

  3. force of friction increases with the decrease of normal force due to increased weight

  4. force of friction is independent of the weight of the body
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The force of friction increases with increase of normal force. Therefore, it is difficult to drag a bucket full of water than an empty bucket.

Multiple choice

Friction cannot be increased by

  1. providing better contact

  2. decreasing roughness

  3. increasing normal force

  4. both (1) and (2)
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Friction can be increased by providing better contact, increasing normal force or by increasing roughness. Friction decreases with decrease in roughness of the surface.

Multiple choice

Which of the following is the cause of friction between two surfaces?

  1. The force of attraction between the two surfaces in contact

  2. The interlocking of the irregularities of the surfaces in contact

  3. The force of repulsion between the two surfaces in contact

  4. The gravitational pull of the earth on the two surfaces
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Friction is caused due to the interlocking of irregularities of the surfaces in contact.

Multiple choice

Which of the following statements is incorrect?

  1. Fluid friction can be minimised by giving suitable shapes to bodies moving in fluids.

  2. The soles of shoes and tyres of vehicles are treaded to decrease friction.

  3. In many machines, friction is reduced by using ball bearings.

  4. It is always easier to roll than to slide a body over another.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The soles of shoes and tyres of vehicles are treaded to increase the grip.

Multiple choice

Even a child can pull a piece of luggage fitted with rollers as compared to the one without rollers. Why?

  1. Because rolling friction is greater than the sliding friction

  2. Because rolling friction is smaller than the sliding friction

  3. Because rolling friction is equal to the sliding friction

  4. Because rolling friction and sliding friction oppose each other
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

It is always easier to roll than to slide a body over another. It is convenient to pull a luggage fitted with rollers as rolling friction is smaller than the sliding friction.

Multiple choice

Why do we slip, when we accidently step on a banana peel?

  1. Because of increased friction

  2. Because of reduced friction

  3. Because of reduced gravitational force

  4. Because of upward reaction
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When we walk, we push the ground backwards with our foot. The tendency of the foot is to move in that direction. The force of friction opposes this tendency and acts in the opposite direction. This helps us to move forward. If the force of friction between our foot and floor is small, our foot may continue to move backwards. In that case, we may slip and fall.

Multiple choice

Which of the following statements is incorrect?

  1. Friction is caused due to interlocking of irregularities on the two surfaces in contact with each other.

  2. Friction is a necessary evil.

  3. Friction cannot be reduced.

  4. Static friction comes into play when we try to move an object at rest.

  5. Rolling friction is always less than sliding friction.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Friction can be reduced by using lubricants, soap solution or by polishing, etc.