Work, Energy and Power · Physics · MHT CET

The power $(\mathrm{P})$ is supplied to a rotating body having moment of inertia ' I ' and angular acceleration ' $\alpha$ '. Its instantaneous angular velocity ' $\omega$ ' is

A simple pendulum of length L has mass m and it oscillates freely with amplitude A. At extreme position, its potential energy is ( $\mathrm{g}=$ acceleration due to gravity)

If the work done in blowing a soap bubble of volume ' V ' is ' W ', then the work done in blowing a soap bubble of volume ' 2 V ' will be

A body of mass 1 kg starts from rest and moves with uniform acceleration. In 2 seconds, its velocity is $10 \mathrm{~m} / \mathrm{s}$. The power exerted on the body in one second is

For a particle moving in vertical circle, the total energy at different positions along the path [The motion is under gravity]

If the momentum of a body of mass ' $m$ ' is increased by $20 \%$ then its kinetic energy increases by

A lead bullet moving with velocity ' V ' strikes a wall and stops. If $75 \%$ of its energy is converted into heat, then the increase in temperature is ( $\mathrm{s}=$ specific heat of lead, $\mathrm{J}=$ mechanical equivalent of heat)

The potential energy of a long spring when it is stretched by 3 cm is ' $U$ '. If the spring is stretched by 9 cm , potential energy stored in it will be

A carpet of mass ' $M$ ' made of a material is rolled along its length in the form of a cylinder of radius ' $R$ ' and kept above the rough floor. If the carpet is unrolled without sliding to a radius ' $R / 2$ '. The change in potential energy is ( $\mathrm{g}=$ acceleration due to gravity)

A ball ' $A$ ' is projected vertically upwards with certain initial speed. Another ball 'B' of same mass is projected at an angle of $30^{\circ}$ with vertical with the same initial speed. At the highest point, the ratio of potential energy of ball A to that of ball B will be

$$\left(\sin 90^{\circ}=1, \sin 60^{\circ}=\cos 30^{\circ}=\frac{\sqrt{3}}{2}, \sin 30^{\circ}=\cos 60^{\circ}=\frac{1}{2}\right)$$

Using variation of force and time given below, final velocity of a particle of mass $$2 \mathrm{~kg}$$ moving with initial velocity $$6 \mathrm{~m} / \mathrm{s}$$ will be

A ball of mass '$$\mathrm{m}$$' is dropped from a height '$$\mathrm{s}$$' on a horizontal platform fixed at the top of a vertical spring. The platform is depressed by a distance '$$h$$'. The spring constant is ( $$\mathrm{g}=$$ acceleration due to gravity)

If a lighter body of mass '$$\mathrm{M}_1$$' and velocity '$$\mathrm{V}_1$$' and a heavy body (mass $$M_2$$ and velocity $$V_2$$ ) have the same kinetic energy then

A stone is projected vertically upwards with speed '$$v$$'. Another stone of same mass is projected at an angle of $$60^{\circ}$$ with the vertical with the same speed '$$v$$'. The ratio of their potential energies at the highest points of their journey is $$\left[\sin 30^{\circ}=\cos 60^{\circ}=0.5, \cos 30^{\circ}=\sin 60^{\circ}=\frac{\sqrt{3}}{2}\right]$$

The kinetic energy of a light body and a heavy body is same. Which one of them has greater momentum?

A stone is projected vertically upwards with velocity 'V. Another stone of same mass is projected at an angle fo $$60^{\circ}$$ with the vertical with the same speed $$(\mathrm{V})$$. The ratio of their potential energies at the highest points of their journey, is

$$\left[\sin 30^{\circ}=\cos 60^{\circ}=0.5, \cos 30^{\circ}=\sin 60^{\circ}=\frac{\sqrt{3}}{2}\right]$$

A car of mass '$$m$$' moving with velocity '$$u$$' on a straight road in a straight line, doubles its velocity in time t. The power delivered by the engine of a car for doubling the velocity is

A bob of a simple pendulum of mass 'm' is displaced through 90$$^\circ$$ from mean position and released. When the bob is at lowest position, the tension in the string is

Three bodies P, Q and R have masses 'm' kg, '2m' kg and '3m' kg respectively. If all the bodies have equal kinetic energy, then greater momentum will be for body/bodies.

A sphere of mass 25 gram is placed on a vertical spring. It is compressed by $$0.2 \mathrm{~m}$$ using a force $$5 \mathrm{~N}$$. When the spring is released, the sphere will reach a height of $$\left(\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^2\right)$$ $$2 \mathrm{~m}$$

A vehicle of mass $$m$$ is moving with momentum $$p$$ on a rough horizontal road. The coefficient of friction between the tyres and the horizontal road is $$\mu$$. The stopping distance is ($$g=$$ acceleration due to gravity)

If the radius of the circular path and frequency of revolution of a particle of mass $m$ are doubled, then the change in its kinetic energy will be $\left(E_i\right.$ and $E_1$ are the initial and final kinetic energies of the particle respectively,)

A force $(F)=-5 \hat{\mathbf{i}}-7 \hat{\mathbf{j}}+3 \hat{\mathbf{k}}$ acting on a particle causes a displacement $(s)=3 \hat{\mathbf{i}}-2 \hat{\mathbf{j}}+a \hat{\mathbf{k}}$ in its own direction. If the work done is 14 J , then the value of ' $a$ ' is