Making Things Work with Mechanical Energy
Many types of energy exist throughout the universe which help hold matter together. Chemical energy allows atoms to bond together. Kinetic energy allows objects to accelerate and decelerate. But how do you explain hitting a baseball with a bat and watching the ball fly in the opposite direction? Mechanical energy allows the transfer of energy from one object to another.
Mechanical Work
Mechanical work is done when mechanical energy is used, such as lifting a stack of papers. This is different from kinetic energy, which only explains acceleration. This energy, on the other hand, transfers energy, in this case from a person's arms to the stack of papers, which uses both kinetic energy to accelerate the stack of papers and mechanical energy to lift the papers away from the center of gravity, in this case the Earth.
Mechanical energy also helps to explain Newton's third law, a physical property most people who have been in a science classroom are familiar with. For every action there is an equal and opposite reaction. Think of a space shuttle flying to the moon. Because the engine generates thrust behind the space shuttle, transferring mechanical energy backwards, the kinetic energy goes forward, and the space shuttle is able to fly through space.
Without mechanical energy, we would not be able to do any work. We could not lift objects, throw balls, or walk. The smallest center of gravity, a speck of dust in space, would be enough to pull us towards it (although we would simultaneously pull it towards us). Kinetic energy would allow us movement, but there would be no way to transfer energy to pick up kinetic energy.
Although all the different types of energy are very different: chemical for holding atoms together in chemical bonds, kinetic for accelerating an object, mechanical for transferring energy, and nuclear for holding the nucleus of an atom together, they are all connected together, exerting forces on each other that we have yet to discover. Ultimately, if we were missing any one of them, we would not be able to function. Without kinetic energy, we would be stuck at whatever speed we were going at. Without chemical energy, we would be a pile of atoms, and objects like the sun would not burn, and chemical reactions would not occur. Without nuclear forces, atoms would disperse into protons, neutrons, and electrons. And without mechanical energy, we would not be able to work against gravity or transfer energy from one object to another. Buildings would never be able to be built. We would simply have to lie down on the ground and be unable to move at all. Without mechanical energy, we would not be able to do much at all.
