Question

Can the total work done on an object during a displacement be negative? Explain. If the total work is negative, can its magnitude be larger than the initial kinetic energy of the object? Explain  

Answer 1

yes, the amount of work done on an object can be negative if it is actually the object that is doing the work, for example, the force is applied in a direction opposite to the direction of motion.

because according to the equation of work done by any displacement,

SO IF THE angle between displacement and direction of the force is negative than work done by the object is negative.

EXAMPLE -- work was done by any mass under gravitation force during vertically upward motion.

2)

no, the amplitude of work has to equal or less than to initial kinetic energy.

since the object will stop after a while under such a force, the total amount of work it can do must be less than or equal to its kinetic energy - the energy stored in the speed of the object.

if the amplitude of work is lesser than initial kinetic energy, the energy stored in the form of its speed.