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

What is the tendency of a moving object to keep moving?

  1. gravity

  2. weight

  3. inertia
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Inertia is the property of matter by which it continues in its existing state of rest or uniform motion in a straight line, unless that state is changed by an external force.

Multiple choice

a force of attraction between all objects.

  1. Telescope

  2. Constellation

  3. Gravity

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

Gravity is the fundamental force of attraction that acts between all objects with mass. It is what keeps planets in orbit and keeps us on the ground.

Multiple choice physics floatation pressure in liquids and gases pressure dependence on force and area concept of pressure

Which Newton's laws describe thrust?

  1. First and second

  2. second and third

  3. only second

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

Thrust is a reaction force described quantitatively by Newton's second and third laws. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction on that system.

Multiple choice physics forces and matter pressure in fluids pressure in liquids introduction to pressure
A fluid exert pressure 

  1. only downwards

  2. only upwards

  3. in all directions

  4. Fluids do not exert pressure
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A fluid is a substance that has no fixed shape and yields easily to external pressure; a gas or  a liquid.

Pressure is exerted by fluids because of their weight. Static fluid pressure is exerted by the depth of the fluid, the density of the fluid and the acceleration of gravity. They exert pressure in all directions, which is given by $F=PA$
where $P$ is the pressure, and $A$ is the area on which force acts.

Multiple choice physics forces and matter pressure in fluids pressure in liquids introduction to pressure

The fluids in a confined space exert pressure in which direction?

  1. Upward

  2. Downward

  3. Forward

  4. All directions
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Pascal's law or the principle of transmission of fluid-pressure is a principle in fluid mechanics that states that pressure exerted anywhere in a confined incompressible fluid is transmitted equally in all directions throughout the fluid such that the pressure variations (initial differences) remain the same.

so option ( D) would be correct

Multiple choice physics forces and matter pressure in fluids pressure in liquids introduction to pressure
Mark the correct Statements.

  1. Solids exert pressure on a surface due to their own weight.

  2. Fluids also have weight.

  3. Liquids can exert pressure.

  4. All the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A fluid is a substance that has no fixed shape, can flow easily and yields easily to external pressure, e.g., a gas or  a liquid.

Pressure is exerted by fluids because of their weight. Static fluid pressure is given by = $\rho \times g \times h $
where $h$ =  depth of the fluid, 
            $\rho$ =  density of the fluid and 
            $g$ = the acceleration due to gravity.
Well knowingly, the solids exert pressure on the surface on which they are placed, given by $P=\dfrac{mg}{A}$
Hence correct answer is option D.

Multiple choice physics behaviour of perfect gas and kinetic theory of gases degree of freedom: law of equipartition of energy law of equipartition of energy law of equipartition of energy and mean free path

The law of equipartition of energy is applicable to the system whose constituents are :

  1. in random motion

  2. in orderly motion

  3. at rest

  4. moving with constant speed
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The original idea of equipartition  is to assign a average kinetic energy to each degree of freedom if we take transnational case only. So if there would be ordered motion instead of random motion then there is no need of equilibrium theorem  as it would be useless to take about averages as they all are in ordered motion.
Hence, the answer is in random motion.
Multiple choice rotational equilibrium option b: engineering physics motion of system of particles and rigid bodies equilibrium physics

Consider the following statements:
(a)  Change in momentum is impulse.
(b)  A body is momentarily at rest when it reverse the direction.
(c)  For stable equilibrium force has to be zero and potential energy should be minimum.
(d)  Force required to accelerate a mass in two perpendicular directions is never same.
Which of the above statements are correct?

  1. (b) and (c)

  2. (a) and (b)

  3. (a), (b) and (d)

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

All of the above
Impulse = Force$\times$time = $m\Delta{v}$ = Momentum
A body will be at rest for a moment when it changes direction.
When a body is in equilibrium it always has minimum potential energy and no force is acting upon it.
Force is a vector quantity and hence its direction will result in different force quantity.

Multiple choice rotational equilibrium option b: engineering physics motion of system of particles and rigid bodies equilibrium physics

When a body remains in the state of rest conditions under the influence of applied forces, the body is in 

  1. Dynamic equilibrium

  2. Static equilibrium

  3. Both

  4. None
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The equilibrium is of two types
(1) Static equilibrium
(2) Dynamic equilibrium
When a body remains in the state of rest under the influence of the applied forces, the body is in static equilibrium.

Multiple choice rotational equilibrium option b: engineering physics motion of system of particles and rigid bodies equilibrium physics

A body is in translatory equilibrium if:

  1. Resultant force on it is zero

  2. It is at rest

  3. It is in uniform motion

  4. All options are correct
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A body is said to be in translatory equilibrium when net external force acting on it is zero.

Also if no external force is acting on the body, then the body must be at rest or moving with constant velocity i.e moves in uniform motion. Hence option D is correct.