In picking upan object from the floor and putting it on a table, we do work. However, the initial and final values ofthe object's kinetic energy are zero. Is there a violation of the work energy theorem here ? Explain why or why not.

If K_(1) and K_(f) are the initial and final value of kinetic energy of a body respectively, then the work done by the net force on the body is equal to

You are reshelving books in a library. You lift a book from the floor to the top shelf. The kinetic energy of the book on the floor was zero and the kinetic energy of the book on the top shelf is zero, so no change occurs in the kinetic energy even though you did some work in lifting the books. Is the work-kinetic energy theorem violated?

A man stands at the centre of a circular platform holding his arms extended horizontally with 4 kg block in each hand. He is set rotating about a vertical axis at 0.5rev//s . The moment of inertia of the man plus platform is 1.6kg-m^(2) , assumed constant, the block are 90 cm from the axis of rotation. He now pulls the blocks in towards his body until they are 15 cm from the axis of rotation. Find (a) his new angular velocity and (b) the initial and final kinetic energy of the man and platform (c) how much work most the man do to pull int he blocks?

A point charge q_(0) is moved slowly from the centre of a ring R, ( that is carrying a charge q) to a distance x from its centre along its axis. What is the work done by the external agent in this process ? Strategy : According to work energy theorem, if there is no change in kinetic energy, we have W_(ext)+ W_(E ) = 0 implies W _(ext) = - W_(E ) = - q_(0)(V_(A)-V_(B))

The potential energy at a point, relative to the reference point is always defined as the negative of work done by the force as the object moves from the reference point to the point considered. The value of potential energy at the reference point itself can be set equal to zero because we are always concerned only with differences of potential energy between two points and the associated change of kinetic energy. A particles A is fixed at origin of a fixed coordinate system. A particle B which is free to move experiences an force vec(F) = (-(2a)/(r^(3)) + (beta)/(r^(2))) hat(r) due to particle A where hat(r) is the position vector of particle B relative to A. It is given that the force is conservative in nature and _potential energy at infinity is zero. If B has to be removed from the influence of A, energy has to be supplied for such a process. The ionization energy E 0 is work that has to be done by an external agent to move the particle from a distance r_(0) to infinity slowly. Here r_(0) is the equilibrium position of the particle If particle B is transferred slowly from point P_(1) (sqrt2 r_(0), sqrt2 r_(0)) to point P_(2) ((r_(0))/(sqrt2), (r_(0))/(sqrt2)) in the xy-plane by an external agent, calculate work required to be done by it in the process:

The potential energy at a point, relative to the reference point is always defined as the negative of work done by the force as the object moves from the reference point to the point considered. The value of potential energy at the reference point itself can be set equal to zero because we are always concerned only with differences of potential energy between two points and the associated change of kinetic energy. A particles A is fixed at origin of a fixed coordinate system. A particle B which is free to move experiences an force vec(F) = (-(2a)/(r^(3)) + (beta)/(r^(2))) hat(r) due to particle A where hat(r) is the position vector of particle B relative to A. It is given that the force is conservative in nature and _potential energy at infinity is zero. If B has to be removed from the influence of A, energy has to be supplied for such a process. The ionization energy E 0 is work that has to be done by an external agent to move the particle from a distance r_(0) to infinity slowly. Here r_(0) is the equilibrium position of the particle What is potential energy function of particle as function of r.

The potential energy at a point, relative to the reference point is always defined as the negative of work done by the force as the object moves from the reference point to the point considered. The value of potential energy at the reference point itself can be set equal to zero because we are always concerned only with differences of potential energy between two points and the associated change of kinetic energy. A particles A is fixed at origin of a fixed coordinate system. A particle B which is free to move experiences an force vec(F) = (-(2a)/(r^(3)) + (beta)/(r^(2))) hat(r) due to particle A where hat(r) is the position vector of particle B relative to A. It is given that the force is conservative in nature and _potential energy at infinity is zero. If B has to be removed from the influence of A, energy has to be supplied for such a process. The ionization energy E 0 is work that has to be done by an external agent to move the particle from a distance r_(0) to infinity slowly. Here r_(0) is the equilibrium position of the particle Find the ionization energy E_(0) of the particle B