Mechanical Energy and Its Different Forms

An object of mass, $m$ is moving with a constant velocity, $v$. How much work should be done on the object in order to bring the object to rest?  

What is the work done by a person while catching a freely falling body? Give reason.

If speed of a car becomes $2$ times, its kinetic energy becomes

The work done to increase the velocity of a car from $30 \mathrm{km} {\mathrm{h}}^{-1}$ to $60 \mathrm{km} {\mathrm{h}}^{-1}$, if the mass of the car is $1500 \mathrm{kg}$, is:

A force acting on a $20 \mathrm{kg}$ mass changes its velocity from $6 \mathrm{m}/\mathrm{s}$ to $3 \mathrm{m}/\mathrm{s}$. The work done by the force is :

Name the three forms of kinetic energy and give one example of each.

A stone of mass $500 \mathrm{g}$is thrown vertically upwards with a velocity of $15 \mathrm{m}/\mathrm{s}$. Calculate the potential energy (in joules) at the greatest height.

A body of mass $60 \mathrm{kg}$ has the momentum $3000 \mathrm{kg} {\mathrm{ms}}^{-1}.$ Calculate the kinetic energy and speed of the body.

A ball of mass $0.5 \mathrm{kg}$ slows down from a speed of $5 {\mathrm{ms}}^{-1}$ to that of $2 {\mathrm{ms}}^{-1}$. Calculate the change in kinetic energy of the ball. 

Calculate the kinetic energy of a body of mass $0.1 \mathrm{kg}$and momentum $20 {\mathrm{kgms}}^{-1}.$ (in joules)

A bullet of mass $5 \mathrm{g}$ travels with a speed of $500 {\mathrm{ms}}^{-1}$. If it penetrates a fixed target which offers a constant resistive force of $1000 \mathrm{N}$ to the motion of the bullet, find the initial kinetic energy (in joules) of the bullet.

Kinetic energy of an object depends on its mass and velocity.

Two bodies A and B of masses $4 \mathrm{kg}$ and $16 \mathrm{kg}$ respectively have same kinetic energy. The ratio of velocity of A and B is:

Two electrodes are maintained at a potential difference of $100\mathrm{V}$. An electron moving from cathode to anode gains kinetic energy equal to

The work done by a body against friction always results in

An object of $40 \mathrm{kg}$ mass is moving with velocity $2 \mathrm{m}/\mathrm{s}$. A force applied to it increases its velocity to $5 \mathrm{m}/\mathrm{s}$. Find the work done by force.

What is energy? Prove that work performed on an object is equal to the difference between initial and final kinetic energies of the object.

An object is moving with uniform velocity $v$. If mass of the object is $m$ then, find how much work needs to be done to bring this object to rest?

When force $\mathrm{F}$ is applied on an object moving with velocity $\mathrm{u}$ then its velocity increases to $\mathrm{v}$. If the distance traveled by the object during this change of velocity is $\mathrm{s}$ then calculate the increase in kinetic energy.

Calculate the speed of the moving proton who kinetic energy is $5 \mathrm{MeV}$. The mass of the proton is $1.6\times {10}^{-27} \mathrm{kg}$ and $1 \mathrm{MeV}=1.6\times {10}^{-13} \mathrm{J}$.