Work, Energy and Power — practice questions
90 curated practice questions from Work, Energy and Power (Physics JEE Advanced, NTA Exams) — 70 hard, 20 medium. Every question includes the final answer free; step-by-step worked solutions with a free account.
- If a person is pushing a box inside a moving train with a force F , the work done in the frame of the earth will be:
- In which of the following cases, no work is done by the force:
- Assertion: Stopping distance = Kinetic energy Stopping force Reason: Work done in stopping a body is equal to KE of the…
- Let f : R → R be given by f ( x ) = ( x – 1)( x – 2)( x – 5). Define F(x)= _ 0 ^ x f(t) d t, x>0 . Then which of the…
- Force acting on a particle is (2 i +3 j ) N. Work done by this force is zero, when a particle is moved on the line 3y +…
- A body is lifted over route I and then route II such that force is always tangent to the path. Coefficient of friction…
- A force of F =2 x i +2 j +3 z^ 2 k N is acting on a particle. Find the work done by this force in displacing the body…
- An object of mass m is tied to a string of length l and a variable horizontal force is applied on it, which starts at…
- A uniform flexible chain of mass m and length 2 l hangs in equilibrium over a smooth horizontal pin of negligible…
- A small particle of mass m moving inside a heavy, hollow and straight tube along the tube axis undergoes elastic…
- The potential energy for a body of mass m that is acted on by a very massive body is given by U=-m g x+ k x^ 3 3 . The…
- A body of mass m is moving in a straight line at a constant speed v. Its kinetic energy is K and the magnitude of its…
- A block of mass m is attached with a massless spring of force constant k. The block is placed over a rough inclined…
- A particle, which is constrained to move along the x -axis, is subjected to a force in the same direction which varies…
- Assertion: Energy released when a mass of one microgram disappears in a process is 9 × 107 J. Reason: It follows from…
- A ball is dropped from a height of 20 cm. Ball rebounds to a height of 10 cm. What is the loss of energy?
- A bob of mass m accelerates uniformly from rest to v1 in time t_ 1 . As a function of t, the instantaneous power…
- The force acting on a body moving along x–axis varies with the position of the particle as shown in the figure. The…
- Assertion: The potential energy of a particle varies with distance x as shown in the graph. The force acting on the…
- A particle is acted by a force F = kx , where k is a +ve constant. Its potential energy at x = 0 is zero. Which curve…
- A block of mass m is being pulled up the rough incline by an agent delivering constant power P. The coefficient of…
- The potential energy function associated with the force F =4 x y t +2 x^ 2 j is
- A spring of stiffness k is kept compressed by applying horizontal force on m by a length x0 (= m g k ) . If the force F…
- A pendulum of mass 1 kg and length = 1 m is released from rest at angle θ = 60° . The power delivered by all the…
- A block of mass m is moving with a constant acceleration ‘a’ on a rough plane. If the coefficient of friction between…
- Two masses of 1 g and 4 g are moving with equal kinetic energy. The ratio of the magnitudes of their momenta is
- A constant power P is applied to a particle of mass m. The distance travelled by the particle when its velocity…
- A motor drives a body along a straight line with a constant force. The power P developed by the motor must vary with…
- A uniform chain AB of mass m and length l is placed with one end A at the highest point of a hemisphere of radius R…
- In the given figure the variation of potential energy of a particle of mass m = 2 kg is represented w.r.t. its…
- A force F acting on a body depends on its displacement S as F ∝ S–1/3 . The power delivered by F will depend on…
- The work done on a particle of mass m by a force, ( K being a constant of appropriate dimensions), when the particle is…
- A force F =(3 x y-5 z) +4 z k is applied on a particle. The work done by the force when the particle moves from point…
- A small ball starts moving from A over a fixed track as shown in the figure. Surface AB has friction. From A to B the…
- A particle moves along the x–axis from x= x1 to x = x2 under the influence of a force given by F = 2x. Work done in the…
- The potential Energy as a function of the force between two atoms in a diatomic molecule is given by U(x)= a x^ 12 - b…
- In the given curved road, if particle is released from A then
- The potential energy for a force field is given by U (x, y) = cos (x + y). The force acting on a particle at position…
- The given plot shows the variation of U, the potential energy of interaction between two particles, with the distance…
- A particle moves in a straight line with retardation proportional to its displacement. Its loss of KE for any…
- Assertion: Under the action of a conservative force of constant magnitude, work done is path independent. Reason: Work…
- Velocity time graph of a particle of mass 2 kg moving in a straight line is as shown in figure. Work done by all forces…
- A man throws the bricks to a height of 12 m where they reach with a speed of 12 m/s. If he throws the bricks such that…
- A vertical spring of force constant 100 N/m is attached with a hanging mass of 10 kg. Now an external force is applied…
- Two inclined frictionless tracks of different inclinations meet at A from where two blocks P and Q of different masses…
- A point mass of 1 kg collides elastically with a stationary point mass of 5 kg. After their collision, the 1 kg mass…
- A particle of mass m is initially at rest at the origin. It is subjected to a force and starts moving along the x…
- A chain (uniform) of mass m and length l has a small block of mass M attached to one of its ends and hangs from the…
- A 500 kg car, moving with a velocity of 36 km h–1 on a straight road unidirectionally, doubles its velocity in one…
- A mass-spring system oscillates such that the mass moves on a rough surface having coefficient of friction μ. It is…
- A small block of mass m is kept on a rough inclined surface of inclination θ fixed in an elevator. The elevator goes up…
- System shown in figure is released from rest. Pulley and spring is massless, and friction is absent everywhere. The…
- A meter stick of mass 400 g is pivoted at one end and displaced through an angle 60°. The increase in its potential…
- Assertion: In a circular motion, work done by centripetal force is not zero always. Reason: If speed of the particle…
- A water cooler of storage capacity 120 litres can cool water at a constant rate of P watts. In a closed circulation…
- A tennis ball is dropped on a horizontal smooth surface. It bounces back to its original position after hitting the…
- A uniform chain of length L and mass M is lying on a smooth table and one third of its length is hanging vertically…
- A force (where K is a positive constant) acts on a particle moving in the xy plane. Starting from the origin, the…
- Velocity-time graph of a particle moving in a straight line is as shown in figure. Mass of the particle is 2 kg. Work…
- A particle of mass m is moving in a circular path of constant radius r such that its centripetal acceleration ( a ) is…
- A bob of mass M is suspended by a massless string of length L . The horizontal velocity V at position A is just…
- Assertion: A weightlifter does not work in holding the weight up. Reason: Work done is zero because distance moved is…
- A uniform rope of linear mass density λ and length l is coiled on a smooth horizontal surface. One end is pulled up…
- The power of a water jet flowing through an orifice of radius r with velocity v is
- Power supplied to a particle of mass 2 kg varies with time as P = 3t2/2 watt, here t is in second. Velocity of particle…
- Assertion: Mass and energy are not conserved separately but are conserved as a single entity ‘mass-energy’. Reason…
- A plank of mass 10 kg and a block of mass 2 kg are placed on a horizontal plane as shown in the figure. There is no…
- A rope ladder with a length l carrying a man with a mass m at its end is attached to the basket of balloon with a mass…
- A dam is situated at a height of 550 m above sea level and supplies water to a powerhouse which is at a height of 50m…
- A machine, which is 75% efficient, uses 12 J of energy in lifting up a 1 kg mass through a certain distance. The mass…
- A uniform chain has a mass M and length L. It is placed on a frictionless table with length l 0 hanging over the edge…
- A block of 4 kg mass starts at rest and slides a distance d down a frictionless incline (angle 30°) where it runs into…
- A particle A of mass 10/7 kg is moving in the positive direction of x. Its initial position is x = 0 and initial…
- A block of mass m is released from a height h1 along a smooth track as shown in the figure. Determine the minimum safe…
- A ship of mass 3 × 10 7 kg initially at rest is pulled by a force of 5 × 10 4 N through a distance of 3 m. Assuming…
- An ideal spring with spring-constant k is hung from the ceiling and a block of mass M is attached to its lower end. The…
- If the speed of a vehicle increases by 2 m/s, its K.E. is doubled. The original speed of the vehicle was
- A plot of velocity versus time is shown in figure. A single force acts on the body. The correct statement is:
- The potential energy of a particle of mass 1 kg is, U = 10 + (x – 2)2 . Here, U is in joules and x in metres on the…
- A mass m is allowed to fall on a pedestal fixed on the top of a vertical spring. If the height of the mass was H from…
- A particle located in a one-dimensional potential field has its potential energy function as U(x) = a x^ 4 - b x^ 2…
- A wind-powered generator converts wind energy into electrical energy. Assume that the generator converts a fixed…
- Two discs, each having mass m, are attached rigidly to the ends of a vertical spring. One of the discs rests on a…
- An engine pumps water continuously through a hole. Speed with which water passes through the hole nozzle is v and k is…
- A ball is released from the top of a tower. The ratio of work done by force of gravity in first, second and third…
- A pulse of light of duration 100 ns is absorbed completely by a small object initially at rest. Power of the pulse is…
- Assertion: Two springs of force constants k1 and k2 are stretched by the same force. If k1 > k2, then work done in…
- A block of mass 2 kg is free to move along the x -axis. It is at rest and from t = 0 onwards it is subjected to a…
- A block of mass m is released from a height h1 along a smooth track as shown in the figure. Determine the force exerted…
- A man raises 1 kg wt. to a height of 100 cm and holds it there for 30 minutes. How much work has he performed?