List of top Physics Questions on Work Power and Energy

The power of a crane, which lifts a mass of 1000 kg to a height of 20 m in 10 s is: (g = 9.8 m/s²)

A \(5\,\text{kg}\) block pushed by \(100\,\text{N}\) over \(10\,\text{m}\) on a plane. If the coefficient of friction between the block and plane is \(0.2\), then the final kinetic energy of the block is _ _ _ (\(g=10\,\text{m s}^{-2}\)):

A force \(F=4x\) is applied to move an object from \(x=0\) to \(x=2\,m\), then the work done is:

A block of mass 3 kg is moving down with constant velocity along a rough inclined plane. The work to be done by an external force in pulling the block along the inclined plane through a height of 50 cm is (Acceleration due to gravity $=10\,ms^{-2}$)

The power \(P\) (in watt) acting on a body of mass \(2\text{ kg}\) is given by \[ 4.5P=8t^2+14t+9 \] where \(t\) is time in second. If the body starts from rest at \(t=0\), then the velocity of the body at time \(t=3\text{ s}\) is

A body is moving in a straight line with constant power. The distance moved by the body in time t is proportional to:

If force, $F=kv^{n}$ (k is constant) and power delivered is independent of velocity 'v', then n equals to:

A spherical ball of mass 2 kg falls from a height of 10 m and is brought to rest after penetrating 10 cm into sand. The average force exerted by sand on the ball is _______ N.}

A body of mass 2 kg is thrown vertically upwards from the ground level with kinetic energy of 240 J. The kinetic energy of the body will become half at a height of (\( g=10 \text{ ms}^{-2} \)):

An object is sliding from the top of the smooth inclined plane of height \( h \) from rest and it just completes a vertical circle of diameter 20 cm. Then the minimum height \( h \) of smooth inclined plane is:

A body of mass 2 kg is thrown vertically upwards from the ground level with kinetic energy of 240 J. The kinetic energy of the body will become half at a height of (\( g=10 \text{ ms}^{-2} \)):

A ball of mass 100 g is projected with velocity 20 $ms^{-1}$ at $60^{\circ}$ with horizontal. The decrease in kinetic energy of the ball during its entire upward journey is:

A block of mass m = 0.1 kg is released from a height of 4 m on a curved smooth surface. On the horizontal surface, path AB is smooth and path BC is rough with a coefficient of friction, $\mu = 0.1$. If the impact of the block with the vertical wall at C is perfectly elastic, the total distance covered by the block on the horizontal surface before coming to rest will be:

A 15 W machine used $(3i + 5j + 6k)$ N force for 6 seconds to lift a body through a distance of X m along x - axis. The value of X is:

A body of mass 3 kg is under a force, which causes a displacement in it given by $S = \frac{t^3}{3}$ (in m). Find the work done by the force in first 2 seconds:

A mass of 1 kg is kept on a inclined plane with $30^\circ$ inclination with respect to horizontal plane and it is at rest initially. Then the whole assembly is moved up with constant velocity of 4 m/s. The work done by the frictional force in time 2 s is \dots J. (Take $g = 10 \text{ m/s}^2$)

The velocity at which \(6\,\text{kg}\) mass (shown in figure) strikes the ground when it is released from a height of \(6\,\text{m}\) above the ground is _____ m/s. Assume pulley is massless and string is light and inextensible. (Take \(g=10\,\text{m/s}^2\)).

A body of mass \(1\,\text{kg}\) moves along a straight line with a velocity \(v=2x^2\). The work done by the body during displacement from \(x=0\) to \(x=5\,\text{m}\) is _____ J.

A body of mass 2 kg begins to move under the influence of time dependent force \(\vec{F} = (2t \hat{i} + 6t^2 \hat{j})\) N, where \(\hat{i}\) and \(\hat{j}\) are unit vectors along x and y-axis respectively. The power produced by the force at \(t = 2\) s is ______ W.

An engine pumps water continuously through a hose pipe. If the water leaves the pipe with velocity $v$ and $m$ is the mass per unit length of the water in the pipe, then the rate at which kinetic energy is imparted to the water is:

The power generated by a turbine operated by the fall of water from a height of 100 m at the rate of $24\text{ kg s}^{-1}$ is 21 kW. The percentage loss in power is

A body of mass 0.2 kg is falling freely from a height of 180 m from the ground. The ratio of the works done by the gravitational force in the first two seconds and in the next two seconds of motion of the body is

A body of mass 50 g is projected vertically upwards from the ground. If the kinetic energy of the body at a height of 32 m is 100% more than its potential energy, then the height at which the potential energy of the body becomes 60% of its kinetic energy is

A bullet of mass $m$ moving with a velocity $u$ gets embedded in a block of mass $M$ initially at rest. If $\mu$ is the coefficient of friction between the block and the ground, then the displacement of the block due to the impact is: