User talk:APDebata

Some questions related to work, power and energy :-

Q1- Can the work done be zero if neither of work and displacement are zero?

Ans:- Yes, it can be, when the angle between force and displacement become π/2.

Q2- When a body goes round a circular path, there is no change in kinetic energy of the body due to the centripetal force, why?

Ans:- Centripetal force is always directed along the radius and is always perpendicular to the displacement (along the tangent) i.e. ϴ=π/2

hence work done =0

thus there is no change in kinetic energy due to the centripetal force.

Q3- When two protons are made closer to each other, what happens to the kinetic energy?

Ans:- When two protons come closer, due to their similar charge, they exhibit a repulsive force, which leads the charges to do work on the system and hence the potential energy of the system increases.

Q4:-An electron and proton have masses in ratio 1:1840. What will be the ratio of kinetic energy, if they have equal momentum?

Ans:- We know that momentum=mv

As electron and proton have equal momentum, meve=mpvp

mp/(m e )=ve/(vp)=1840

ke/kp =((1/2) meve)2/((1/2) mp vpp2 )=1/(1840)2 ×1840 =1840