A box of mass M is pushed a distance Δ x across a level floor by a constant applied force F . The coefficient of kinetic friction between the box and the floor is μ . Assuming the box starts from rest, express the final velocity v f of the box in terms of M , Δ x , F , μ , and g .

Final speed of the box after moving the given distance is

Explanation:

By work energy theorem we know that work done by all the forces is equal to the change in kinetic energy of the system

Here we know that work is done on the system by external force and friction force

So we will have

so we have

it is the second option.

the motion of a pendulum is a classic example of mechanical energy conservation. a pendulum consists of a mass (known as a bob ) attached by a string to a pivot point. as the pendulum moves it sweeps out a circular arc, moving back and forth in a periodic fashion.