In physics, work is energy that is transferred from an entity to another through the application of pressure or force along a change in displacement. In its most basic form, it can be defined as the product of pressure and displacement. Force and displacement are always used when speaking of work; however, other types of energy are sometimes used as well. Examples of these include light, heat, electricity, magnetism, sound, nuclear fission, and friction.
The concept of work can be described in four different forms: force, power, time, and position. For example, if I pick up a bowling ball, with my weight and strength, and let it roll down the hill a number of times, and then release it, where will the force of attraction and the force of repulsion end up? This question assumes that the bowling ball is being held at the average velocity of the downward slope. To solve for the particular amount of work, one must determine the distance between the point where the bowling ball stopped and the center of the earth. Measure the size of this circle, and then calculate the magnification by multiplying the distance by the area of the circle.
One way to solve for the amount of work done is to determine if the work is in a straight line, or if it has an inclination to the left or the right. If it has an inclination to the right, the component of the force in the direction of motion must be more in the right direction. For example, when the bowling ball rolls downward in a downward direction, the force acting on the ball due to gravity will be more in the direction of the downhill slope.
The second component of the force in the direction of motion is the displacement, which is the measured distance from the point where the bowling ball stopped to the location where it ended up. This distance, which is also called the travel time, can be figured out by dividing the total displacement by the total height that the object had while in its horizontal position. That is, if the bowling ball stops at t, then the distance traveled in its horizontal travel is t times the product of the height t times the square of the distance travelled in its vertical travel. This formula can be used for any arbitrarily defined displacement.
Finally, the third component of the force in the direction of motion is the impulse, which is the change in velocity due to gravity, air resistance, or any other force acting on the system that causes instantaneous movement. Again, the formula for calculating the impulse is simply the product of the initial displacement and the final displacement, times the square of the velocity. For the force f, the impulse is the integral of the impulse due to gravity and the change in velocity due to air resistance, divided by the height of the body from which the force is being applied. Therefore, the impulse is the component of the force in the direction of motion that produces the greatest overall reaction.
The components of the force in the direction of motion are, more often than not, derived from the integral formula for finding the derivative of a function, namely the displacement, with respect to a fixed reference frame. That is, the magnitude of the displacement as it changes with time is the function of the force, whose component in the direction of motion must be constant. Applying the right relationships to these components of the force will help one to determine the value of the force, which in turn will give one the value for work done.