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 newton's laws of motion momentum (p) introduction to momentum linear momentum

An example of a force applied in the direction of motion is:

  1. Opening a door

  2. Applying brakes suddenly to a moving car

  3. A batsman hitting a cricket ball

  4. Drawing water from a well
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

While opening the door the force applied is tangential to the motion of the door.
While applying brakes the motion is on a different axis to the force applied,
When a batsman hits a ball, both the ball and the force applied are in the same direction
While drawing water from the well the motion and the force are in different directions (mostly tangential)

Multiple choice physics force and newton's laws of motion momentum (p) introduction to momentum linear momentum

The quantity that best represents the motion of a rigid body is

  1. its mass.

  2. its speed.

  3. its velocity.

  4. its linear momentum.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Mass of a body is the quantity of inertia possessed by it, or in simpler words, it is the measure of resistance that a body can provide to change in its motion.
Speed is the measure of how fast a body is moving.
Velocity is the measure of how fast a body is moving along with its direction.
Linear momentum is the quantity which denoted the motion of body along with its direction.

Multiple choice physics force and newton's laws of motion momentum (p) introduction to momentum linear momentum

In which of the following cases the net force is not zero?

  1. A kite skillfully held stationary in the sky

  2. A ball freely falling from a height
  3. An aeroplane rising upwards at an angle of $45^{\circ}$ with the horizontal with a constant speed

  4. A cork floating on the surface of water
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

If a ball freely falling from a height the net force applied on the ball is not zero as gravity is acting on it.

Multiple choice physics force and newton's laws of motion momentum (p) introduction to momentum linear momentum

What does the principle of conservation of linear momentum state?

  1. The linear momentum of a system cannot be changed.

  2. The linear momentum of a system cannot remain constant.

  3. The linear momentum of a system can be changed only if internal forces act.

  4. The linear momentum of a system can be changed only if external forces acts on it.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The principle of conservation of linear momentum states that the linear momentum of a system can be changed only if external forces acts on it.

Multiple choice physics force and newton's laws of motion momentum (p) introduction to momentum linear momentum
State whether true or false.
If the same force is applied on two bodies of different masses for the same time, then the change produced in the momentum of the two bodies is also the same.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let A and B be two bodies and F be the force for t time duration.

    $a _{A}=\frac{F}{M _{A}}$  ,$a _{B}=\frac{F}{M _{B}}$
$V _{A}$ (after t)$=\frac{F _{t}}{M _{A}}$
$V _{B}$ (after t)$=\frac{F _{t}}{M _{B}}$
Momentum of A $=M _{A}V _{A}=Ft$
Momentum of B $=M _{B}V _{B}=Ft$

Multiple choice physics force and newton's laws of motion momentum (p) introduction to momentum linear momentum

Momentum is a measure of:

  1. weight

  2. mass

  3. quantity of motion

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

In order to stop a moving body we require a force and depends on the velocity as well as its mass. It was Newton in his second law who defined this new quantity as momentum.
Momentum is the product of mass and velocity of the body or in other words momentum is the measure of quantity of motion.

Multiple choice physics force and newton's laws of motion momentum (p) introduction to momentum linear momentum

State whether true or false.
If two bodies of different masses move with the same momentum, then the heavier body will have the greater velocity.

  1. True

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

If two bodies of different masses move with the same momentum, then the heavier body will not have the greater velocity.

Hence,
option $B$ is correct answer.

Multiple choice

Which scenario shows elastic potential energy transforming into kinetic energy?

  1. extending a rubber band, then releasing it

  2. a bike being ridden uphill

  3. an eagle in a nest that starts to fly

  4. writing on paper with a pencil
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A rubber band stores elastic potential energy when stretched; when released, that energy is converted into the kinetic energy of the band moving. The other options involve gravitational potential energy or chemical energy.