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 physics force and types of force introduction to force what is force? concept of force and its unit

Fill in the blanks .
At least _____________ object must interact for a force to come into play. 

  1. 1

  2. 2

  3. 3

  4. 4
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Forces are used in our daily life actions like pushing, pulling, lifting, twisting etc. So, a force is a pull or push acting on an object which tends to change the state of rest/ motion of an object. An interaction of one object with another object results in a force between the two objects.

For example, Weightlifter uses muscular force to lift the weights.

Hence, At least 2 object must interact for a force to come into play. 

Multiple choice physics force and types of force introduction to force what is force? concept of force and its unit

Which one of the following statements regarding Newton's first law of motion is incorrect?

  1. It is an independent statement

  2. it defines an inertial frame of reference

  3. It was first enunciated by Galileo

  4. It is a special case of Newton's second law.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Newton's first law is not an independent statement because it is a special case of the second law (where F=0, a=0). It defines inertial frames, but it is derived from the broader scope of the second law.

Multiple choice physics force and types of force introduction to force what is force? concept of force and its unit

Which statement defines force?

  1. When a force acts on a body that is free to move, the force is the product of the mass of the body and its acceleration

  2. When a force acts on a body that is free to move, the force is the rate of change of momentum of the body

  3. When a force acts on a body that is free to move, the force is the work done by the force divided by the distance moved by the body

  4. When a force acts on a lever and causes a moment, the force is the moment divided by the perpendicular distance of the force from the pivot
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

we know that 

$F= ma $ ..........(1)
and $a = \dfrac{dv}{dt}$
So from above eqn . 
$\implies F = \dfrac{mdv}{dt}$
$\implies F = \dfrac{dmv}{dt}$
$\implies F = \dfrac{dp}{dt}$
So, force = rate of change of momentum

Multiple choice physics force and types of force introduction to force what is force? concept of force and its unit

A force cannot be seen but the effect of force can be felt.

  1. True

  2. False

  3. Ambiguous

  4. Data insufficient
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

According to Newton's first law, force is the rate of change of momentum.
Therefore, a force is not a physical object that can be seen. However, the effect of a force on an object can be seen (i.e its changing momentum)

Multiple choice physics force and types of force introduction to force what is force? concept of force and its unit

Which of the following class of forces is different from others?

  1. Pulling of a cart

  2. Stretching of a coiled spring

  3. Kicking of a football

  4. Weight of the body
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Pulling of a cart, stretching of a coiled spring and kicking of a ball take place due to contact forces but weight of the body (gravitational force) is a non-contact force.

Hence option D is correct.

Multiple choice physics force and types of force introduction to force what is force? concept of force and its unit

In which of the following cases, a force is not being applied?

  1. A man standing behind a stationary car.

  2. A car being pushed by a man.

  3. A man trying to stop a sliding car.

  4. A man standing on a car.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

For pushing a car, a force is required in the direction of motion of the car. 

In trying to stop a sliding car, a force is required against the direction of motion of the car. 
A man standing on the car applies the force of weight on the car.
But, to stand behind a stationary car, no net force needs to be applied in the car.
Option A