JEE Main Physics — Mechanics previous year questions with solutions.
A block of mass $10\mathrm{kg}$ is moving along $x$-axis under the action of force $F=5xN$. The work done by the force in moving the block from $x=2m$ to $4m$ will be _______ $J$.
If the maximum load carried by an elevator is $1400\mathrm{kg}$ $(600\mathrm{kg}\text{-Passengers}+800\mathrm{kg}\text{-elevator})$ , which is moving up with a uniform speed of $3m{s}^{-1}$ and the frictional force acting on it is $2000N$, then the maximum power used by the motor is _____________$\mathrm{kW}.(g=10m{s}^{-2})$
A bullet of mass $0.1\mathrm{kg}$ moving horizontally with speed $400m{s}^{-1}$ hits a wooden block of mass $3.9\mathrm{kg}$ kept on a horizontal rough surface. The bullet gets embedded into the block and moves $20m$ before coming to rest. The coefficient of friction between the block and the surface is _______.
A body of mass $5\mathrm{kg}$ is moving with a momentum of $10\mathrm{kg}m{s}^{-1}$. Now a force of $2N$ acts on the body in the direction of its motion for $5s$. The increase in the Kinetic energy of the body is _____ $J$.
A body is dropped on ground from a height ${h}_{1}$ and after hitting the ground, it rebounds to a height ${h}_{2}$. If the ratio of velocities of the body just before and after hitting ground is $4$, then percentage loss in kinetic energy of the body is $\frac{x}{4}$. The value of $x$ is _____.
A force $F=(5+3{y}^{2})$ acts on a particle in the $y$-direction, where $F$ is newton and $y$ is in meter. The work done by the force during a displacement from $y=2m$ to $y=5m$ is ______ $J$.
A small particle moves to position $5\hat{i}-2\hat{j}+\hat{k}$ from its initial position $2\hat{i}+3\hat{j}-4\hat{k}$ under the action of force $5\hat{i}+2\hat{j}+7\hat{k}N$. The value of work done will be ______ $J$.
Identify the correct statements from the following: (A) Work done by a man in lifting a bucket out of a well by means of a rope tied to the bucket is negative (B) Work done by gravitational force in lifting a bucket out of a well by a rope tied to the bucket is negative (C) Work done by friction on a body sliding down an inclined plane is positive (D) Work done by an applied force on a body moving on a rough horizontal plane with uniform velocity is zero (E) Work done by the air resistance on an oscillating pendulum is negative Choose the correct answer from the options given below:
A body of mass $1\mathrm{kg}$ begins to move under the action of a time dependent force $\vec{F}=(t\hat{i}+3{t}^{2}\hat{j})N$, where $\hat{i}$ and $\hat{j}$ are the unit vectors along $x$ and $y$ axis. The power developed by above force, at the time $t=2s$, will be _______$W$.
A body is moving with constant speed, in a circle of radius $10m$. The body completes one revolution in $4s$. At the end of $3rd$ second, the displacement of body (in $m$) from its starting point is:
A vector in $x-y$ plane makes an angle of ${30}^{o}$ with $y$-axis. The magnitude of $y$-component of vector is $2\sqrt{3}$. The magnitude of $x$-component of the vector will be :
A bullet of $10g$ leaves the barrel of gun with a velocity of $600m{s}^{-1}$. If the barrel of gun is $50\mathrm{cm}$ long and mass of gun is $3\mathrm{kg},$ then value of impulse supplied to the gun will be:
A particle of mass $m$ moving with velocity $v$ collides with a stationary particle of mass $2m$. After collision, they stick together and continue to move together with velocity
A machine gun of mass $10\mathrm{kg}$ fires $20g$ bullets at the rate of $180$ bullets per minute with a speed of $100m{s}^{–1}$ each. The recoil velocity of the gun is :
Match List I with List II <table class="pyq-table"><tbody><tr><td></td><td>List</td><td></td><td>List II</td></tr><tr><td>A</td><td>Young's Modulus $(Y)$</td><td>I</td><td>$[{\mathrm{ML}}^{–1}T{}^{–1}]$</td></tr><tr><td>B</td><td>Co-efficient of Viscosity $(\eta )$</td><td>II</td><td>$[{\mathrm{ML}}^{2}T{}^{–1}]$</td></tr><tr><td>C</td><td>Planck's Constant $(h)$</td><td>III</td><td>$[{\mathrm{ML}}^{–1}T{}^{–2}]$</td></tr><tr><td>D</td><td>Work Function $(\phi )$</td><td>IV</td><td>$[{\mathrm{ML}}^{2}{T}^{–2}]$</td></tr></tbody></table>Choose the correct answer from the options given below:
The speed of a wave produced in water is given by $\nu ={\lambda }^{a}{g}^{b}{\rho }^{c}$. Where $\lambda ,g$ and $\rho$ are wavelength of wave, acceleration due to gravity and density of water respectively. The values of $a,b$ and $c$ respectively, are
Match List I with List II <table class="pyq-table"><tbody><tr><td></td><td>List I</td><td></td><td>List II</td></tr><tr><td>A</td><td>Torque</td><td>I</td><td>$\mathrm{kg}{m}^{–1}{s}^{–2}$</td></tr><tr><td>B</td><td>Energy density</td><td>II</td><td>$\mathrm{kg}m{s}^{–1}$</td></tr><tr><td>C</td><td>Pressure gradient</td><td>III</td><td>$\mathrm{kg}{m}^{–2}{s}^{–2}$</td></tr><tr><td>D</td><td>Impulse</td><td>IV</td><td>$\mathrm{kg}{m}^{2}{s}^{–2}$</td></tr></tbody></table>Choose the correct answer from the options given below :
A vector in $x-y$ plane makes an angle of ${30}^{o}$ with $y$-axis. The magnitude of $y$-component of vector is $2\sqrt{3}$. The magnitude of $x$-component of the vector will be :
Given below are two statements: Statement-I: An elevator can go up or down with uniform speed when its weight is balanced with the tension of its cable. Statement-II: Force exerted by the floor of an elevator on the foot of a person standing on it is more than his/her weight when the elevator goes down with increasing speed. In the light of the above statements, choose the correct answer from the options given below:
The initial speed of a projectile fired from ground is $u$. At the highest point during its motion, the speed of projectile is $\frac{\sqrt{3}}{2}u$. The time of flight of the projectile is:
The ratio of powers of two motors is $\frac{3\sqrt{x}}{\sqrt{x+1}},$ that are capable of raising $300\mathrm{kg}$ water in $5$ minutes and $50\mathrm{kg}$ water in $2$ minutes respectively from a well of $100m$ deep. The value of $x$ will be
A force of $-P\hat{k}$ acts on the origin of the coordinate system. The torque about the point $(2,-3)$ is $P(a\hat{i}+b\hat{j})$, The ratio of $\frac{a}{b}$ is $\frac{x}{2}$. The value of $x$ is
Moment of inertia of a disc of mass $M$ and radius '$R$' about any of its diameter is $\frac{M{R}^{2}}{4}$. The moment of inertia of this disc about an axis normal to the disc and passing through a point on its edge will be, $\frac{x}{2}M{R}^{2}$. The value of $x$ is ______.
Two identical solid spheres each of mass $2\mathrm{kg}$ and radii $10\mathrm{cm}$are fixed at the ends of a light rod. The separation between the centres of the spheres is $40\mathrm{cm}.$ The moment of inertia of the system about an axis perpendicular to the rod passing through its middle point is$______\times {10}^{–3}\mathrm{kg}{m}^{2}.$