Question 1 :
A bullet is fired normally on a wooden plank, which is immovable. It loses 25% of its momentum in penetrating a thickness of 3.5 cm the total thickness penetrated by the bullet is
Question 2 : A bead of mass {tex} m {/tex} is sliding down the fixed inclined rod without friction. It is connected to a point {tex} P {/tex} on the horizontal surface with a light spring of spring constant {tex} k . {/tex} The bead is initially released from rest and the spring is initially unstressed and vertical. The bead just stops at the bottom of the inclined rod. Find the angle which the inclined rod makes with horizontal.<br><img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5e0ee77bdc973f528b538d17">
Question 3 :
Kilowatt is the unit of electrical _______ but kilowatt-hour is the unit of electrical _______.<br/>
Question 4 :
An automobile of mass m accelerates from rest. If the engine supplies constant power p, the velocity at time t is given by
Question 5 :
A lamp rated $20w$ and an electric iron rated $50w$ are used for $2$ hour everyday. Calculate the total energy consumed in $20 days.$
Question 6 :
Forces acting on a particle have magnitudes of 14, 7, and 7 N and act in the direction of vectors $6\hat { i } +2\hat { j } +3\hat { k } ,\quad 3\hat { i } -2\hat { j } +6\hat { k } ,\quad 2\hat { i } -3\hat { j } -6\hat { k } $ respectively. The forces remain constant while the particle is displaced from point A: (2, 1, -3) to B: (5, 1, 1). Find the work done. The coordinates are specified in meters.<br/>
Question 7 :
A rope is used to lower vertically a block of mass M at a distance x at a constant downward acceleration $g/2$. The work done by the rope on the block is:
Question 8 :
A force $F = ( 6 i - 8 j ) N ,$ acts on a particle and displaces it over $4 \mathrm { m }$ along the X-axis and $6 m$ along the Y-axis. The total work done during the two displacements is:<br/>
Question 9 :
A force of(5+3x)N acting on a body of mass 20 kg along the x-axis displaces it from x=2m to x=6m.The Work done by the force is
Question 10 :
An electric pump is used to fill an overhead tank of capacity {tex} 9 \mathrm { m } ^ { 3 } {/tex} kept at a height of {tex} 10 \mathrm { m } {/tex} above the ground. If the pump takes {tex}5{/tex} minutes to fill the tank by consuming {tex} 10 \mathrm { k } W {/tex} power the efficiency of the pump should be {tex} \left( \mathrm { g } = 10 \mathrm { ms } ^ { - 2 } \right) {/tex}
Question 11 :
A body of mass m kg initially at rest attains a velocity of $v\:m/s$ in time t under the action of a constant force F. The power supplied to the mass is:
Question 12 :
Rate of doing work is directly proportional to time taken to do the work.<br>
Question 13 :
A body of mass $m$ when released from a height $h$, hits the ground with speed $\sqrt{gh}$. Find work done by resistive force.
Question 14 :
A {tex} 10 \mathrm { m } {/tex} long iron chain of linear mass density {tex} 0.8 \ \mathrm {kg m^{-1}}{/tex} is hanging freely from a rigid support. If {tex} \mathrm { kg } \mathrm { m } ^ { - 1 } {/tex} is hanging freely from a rigid support. If {tex} \mathrm { g } = 10 \mathrm { ms } ^ { - 2 } , {/tex} then the power required to left the chain upto the point of support in 10 second
Question 15 : Mass {tex} m _ { 1 } {/tex} strikes {tex} m _ { 2 } {/tex} which is at rest. The ratio of masses for which they will collide again (collision between ball and wall are elastic, coefficient of restitution between {tex} m _ { 1 } {/tex} and {tex} m _ { 2 } {/tex} is {tex} e {/tex} and all the surfaces are smooth.)<br><img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5e0ee807dc973f528b538d7a"><br>
Question 16 :
A cord is used to raise a block of mass $m$ vertically through a distance $d$ at a constant downward acceleration $g/4$. The work done by the cord is:
Question 17 :
The kinetic energy of a body is increased by 300%. What is the percentage increase in the momentum of the body?
Question 18 :
A block of mass {tex} 0.50 \mathrm { kg } {/tex} is moving with a speed of {tex} 2.00 \mathrm { ms } ^ { - 1 } {/tex} on a smooth surface. It strikes another mass of {tex} 1.00 \mathrm { kg } {/tex} and they move together as a single body. The energy loss during the collision is
Question 19 :
A pump having efficiency 75% lifts 800 kg water per minute from a 14 m deep well and throws at a speed of 18 ms$^{-1}$. Find the power of the pump.
Question 20 :
A body projected vertically from the earth reaches a height equal to earth’s radius before returning to the earth. The power exerted by the gravitational force is greatest
Question 21 :
The work done in holding 15 kg suitcase while waiting for a bus for 45 minutes is: <br>
Question 22 :
A body of mass {tex} m {/tex} is accelerated uniformly from rest to a speed {tex} v {/tex} in a time {tex} T {/tex}. The instantaneous power delivered to the body as a function of time is given by
Question 23 :
The heart of a man pumps $5$ litres of blood through the arteries per minute at a pressure of $150 mm$ of mercury. If the density of mercury be $13.6 \times 10^3\,kg/m^3$ and $g=10 \, m/s^2$ then the power of heart in watt is:
Question 24 :
A ball is moved along a straight line by a machine delivering constant power. The distance moved by the body in time t is proportional to
Question 25 :
Two coolies $ A $ and $B$ do some work in time $ 1$ minute and $ 2 $ minute respectively. The power spent is
Question 26 :
Energy released in the fission of a single $_{92}U^{235}$ nucleus is $200\ MeV$. The fission rate of $_{92}U^{235}$ fuelled reactor operating at a power level of $5\ watt$ is
Question 27 :
A water-pump driven by petrol raises water water at a rate of $0.5\:m^{3}/min$ from a depth of 30 m. If the pump is 70% efficient, what power is developed by the engine-<br>
Question 28 :
75 kW engine is generating full power. It is able to provide a 700 kg airplane a speed 2.5 ms$^{-1}$. Find the fraction of engine power used.
Question 29 :
A car of mass 1000 kg accelerates uniformly from rest to a velocity of 54 km/hour in 5s. The average power of the engine during this period in watts is (neglect friction)
Question 30 :
A particle moves with a velocity $\vec v=(5\hat i-3\hat j+6\hat k) ms^{-1}$ under the influence of a constant force $\vec F=(10\hat i+10\hat j+20\hat k)N$. The instantaneous power applied to the particle is
Question 31 :
Assertion: Power of a constant force is also constant.
Reason: Net constant force will always produce a constant acceleration.
Question 32 :
A pump motor is used to deliver water at a certain rate from a given pipe. To obtain twice as much water from the same pipe in the same time, power of the motor has
to be increased to
Question 33 :
A wind-powered generator converts wind energy into electrical energy. Assume that the generator converts a fixed fraction of the wind energy intercepted by its blades into electrical energy. For wind speed {tex} v , {/tex} the electrical power output will be proportional to
Question 34 :
A stone is dropped from the top of a tall tower. The ratio of the kinetic energy of the stone at the end of three seconds to the increase in the kinetic energy of the stone during the next three seconds is
Question 35 :
Number of kilowatt-hours =$\dfrac { volt\times ampere\times time }{ 1000 } $. Then:<br/>
Question 36 :
A body is moving unidirectionally under the influence of a source of constant power. Its displacement in time t is proportional to
Question 37 : A pump of $200W$ power is lifting $2kg$ water from an average depth of $10m$ in one second. Velocity of water delivered by the pump is :<div>$(g=10m/s^2)$</div>
Question 38 :
A body of mass 2 kg moving on a horizontal surface with an initial velocity of 4 m/s comes to rest after 2 s. If one wants to keep this body moving on the same surface with a velocity of 4 m/s, the force required is:
Question 39 :
Power of gravitational force of a projectile at its highest point of the path is
Question 40 :
Write true or false for the following statements:<br>A force does not work, if it produces no motion.
Question 41 :
A force $F = (5 \hat {i} + 3\hat {j})$ newtons is applied over a particle which displaces it from its origin to the point $r = (2\hat {i} - 1\hat {j})$ metres. The work done on the particle is
Question 42 :
How much work must be done by a force on $50\ $ <br> $kg$ body in order to accelerate it from rest to $20\ m/s$  in $10\ $ <br> $s$ ?
Question 43 :
A particle of mass {tex} 10 \mathrm { g } {/tex} moves along a circle of radius {tex} 6.4 \mathrm { cm } {/tex} with constant tangential acceleration. What is the magnitude of this acceleration if the kinetic energy ofthe particle becomes equal to {tex}8 \times 10^{-4} \mathrm J {/tex} by the end or the second revolution after the inning of the motion ?
Question 44 :
A block is displaced from (1m, 4m, 6m) to $\displaystyle \left ( 2\hat{i}+3\hat{j}-4\hat{k} \right )$ m under a constant force $\displaystyle \vec{F}= \left ( 6\hat{i}-2\hat{j}+\hat{k} \right )N.$ Find the work done by this force.
Question 45 :
A car of mass m starts from rest and accelerates so that the instantaneous power delivered to the car has a constant magnitude $P_{0}$. The instantaneous velocity of this car is proportional to:<br/>
