Principle of Work and Energy

Well, I've just did several questions from the exercise books from the university.

The questions are pretty straightforward. However, there are several skills that I need to brush up before feeling so confident about myself.

1- I have to first understand what the question wants then apply the principles I've learnt

2- The direction of the force or vector has to be taken into consideration. If it's opposing the direction in which the force of gravity is acting, then it is negative.

3-All forces resolved vertically, if there's a friction on the plane, it will have to be taken into consideration

Principle of Work and Energy

1. The work done on an object as it moves between two positions equals the change in its kinetic energy.
2. Princple of work and energy permits us to determine the change in the magnitude of the object's velocity.
3. This principle relates to a change in the position of an object to the change in its velocity.
4. However, it is not convenient for obtaining the time it takes the object to move from one position to another.