Energy, Work, & Power

Work ► refers to an activity involving a force and movement in the directon of the force. A force of 20 newtons pushing an object 5 meters in the direction of the force does 100 joules of work.

Force ► force may be thought of as any influence which tends to change the motion of an object.

Mechanical Force ► In mechanics, forces are seen as the causes of linear motion, whereas the causes of rotational motion are called torques. The action of forces in causing motion is described by Newton's Laws under ordinary conditions, although there are notable exceptions. rotational motiontorquesNewton's Laws rotational motiontorquesNewton's Laws

Energy ► is the capacity for doing work. You must have energy to accomplish work - it is like the "currency" for performing work. To do 100 joules of work, you must expend 100 joules of energy.

Power ► is the rate of doing work or the rate of using energy, which are numerically the same. If you do 100 joules of work in one second (using 100 joules of energy), the power is 100 watts.

Rate of doing Work ► The rate of doing work is equal to the rate of using energy since the a force transfers one unit of energy when it does one unit of work. A horsepower is equal to 550 ft lb/s, and a kilowatt is 1000 watts. workenergyworkenergy

First Law ► The first law says that an object at rest tends to stay at rest. An object in motion tends to stay in motion, in the same direction and speed. speed

Second Law ► The second law says that the acceleration of an object produced by a force is directly proportional to the magnitude of the force, the same direction as the force, and inversely proportional to the mass of the object. acceleration Inversely proportional means that if one value goes up the other value will go down, assuming everything else stays the same.

Third Law ► The third law says that for every action there is an equal and opposite reaction.