Laws of motion practice · Mixed difficulty

The one which does not represent a force in any context is

A cyclist bends while taking turn in order to

Which of the following statement (s) is/are correct?

I. A string has a mass $m$. If it is accelerated, tension is non-uniform and if it is not accelerated, tension is uniform.

II. Tension force is an electromagnetic force.

Which of the following is NOT a fundamental force in nature?

A body starts sliding down an inclined plane of inclination $30^{\circ}$. The upper part of length $2 {~m}$ is smooth and lower part of length $4 {~m}$ is rough. The coefficient of friction between the plane and the body, if the body is brought to rest just when it reaches the bottom

On a banked road, which force is essential to provide the necessary centripetal force to a car to take a turn while driving at the optimum speed?

Statement I: A car is moving in a horizontal circular plane with varying speed, then the frictional force is neither pointing towards the radial direction nor along the tangential direction.
Statement II: Components of the frictional force are providing the necessary tangential and centripetal acceleration, in the above situation.

Which one of the following is not used to reduce friction

A vehicle of mass 120 kg is moving with a uniform velocity of 108 $\;\mathrm{km}{\mathrm{h}^{ - 1}}$. The force required to step the vehicle in 10 s is

An object of mass $3 {~kg}$ is at rest. Now a force of $\vec{F}=6 t^2 \hat{i}+4 t \hat{j}$ is applied on the object then the velocity of the object at $t=3 {~s}$ is

The object at rest suddenly explodes into three parts with the mass ratio 2:1:1. The parts of equal masses move at right angles to each other with equal speed ‘$v$’. The speed of the third part after explosion will be

Human heart is pumping blood with constant velocity $v\,m\,{s^{ - 1}}$ at the rate of $M\,kg\,{s^{ - 1}}.$ The force required for this is (in $N$)

Assertion: The weighing machine measures the weight of a body.
Reason: Weightlessness means the absence of weight.

In a non-inertial frame, the second law of motion is written as
where, $\mathbf{F}_p$ is pseudo force while $\mathbf{a}$ is the acceleration of the body relative to the non-inertial frame.

A machine gun fires a bullet of 10 g with a speed of $100\,m{s^{ - 1}}.$ A person holding the gun can exert a maximum force of 100 N on it. The number of bullets that can be fired from the gun per second is

A metre scale is moving with uniform velocity. This implies

A force vector applied on a mass is represented as $\vec{F}=(6 \hat{i}-8 \hat{j}+10 \hat{k}) \mathrm{N}$ and accelerates with $1 \mathrm{~m} / \mathrm{sec}^2$. What will be the mass of the body?

If a person with a spring balance and a body hanging from it goes up and up in an aeroplane, then the reading of the weight of the body as indicated by the spring balance will

A rocket of initial mass $6,000 \mathrm{~kg}$ ejects mass at a constant rate of $16 \mathrm{~kg} \mathrm{~s}^{-1}$ with constant relative speed of $11 \mathrm{kms}^{-1}$. What is acceleration of the rocket a minute after the blast? Neglect gravity.

At a certain instant of time the mass of rocket going up vertically is 100 kg. If it is ejecting 5 kg of gas per second at a speed of 400 m/s, the acceleration of the rocket would be (Taking $g = 10\;\mathrm{m}/{\mathrm{s}^2})$

A minimum force $F$ is applied to a block of mass $102 \mathrm{~kg}$ to prevent it from sliding on a plane with an inclination angle $30^{\circ}$ with the horizontal. If the coefficients of static and kinetic friction between the block and the plane are $0.4$ and $0.3$ respectively, then the force $F$ is

An object of mass $15 {~kg}$ moves at a constant speed of $15 {~ms}^{-1}$. A constant force, which acts for 5 seconds on the object gives it a speed 5 ${ms}^{-1}$ in opposite direction. The force acting on the object is?

Assertion: Rocket in flight is not an illustration of projectile.

Reason: Rocket takes flight due to combustion of fuel and does not move under the gravity effect alone

When a train takes a turn, the passengers are thrown outwards because of-

Units of impulse is

If the coefficient of friction is 1, the angle of friction is

Assertion: To conserve linear momentum of a system, no force should act on the system.

Reason: If net force on a system is zero, its linear momentum should remain constant.

A force is applied for a duration of 10 seconds on a body of mass 5 kg that is at rest. As a result the body acquires a velocity of $2\,m{s^{ - 1}}$. Find the magnitude of the force applied

A body under the action of a force $\bar F = 9i - 6j + 8k$ acquires an acceleration of $2\,\,m/{s^2}.$ The mass of this body be

A book of weight 20 N is pressed between two hands and each hand exerts a force of 40 N. If the book just starts to slide down. Coefficient of friction is