Physics

Electrons carry a negative charge.

Any of the basic mechanical devices for applying a force are called simple machines._x000D_ There are 6 basic simple machines; the lever, the wheel and axle, the inclined plane, the wedge, the pulley, and the screw. Several of these simple machines are related to each other. But, each has a specific purpose in the world of doing work. A pair of scissors is not a simple machine.

Q = mcdT refers to Specific Heat formula.

The plastic material commonly used for making gear wheels is nylons.

The concept of mass defect comes from the concept of nuclear binding energy, which is the energy required to disassemble the nucleus of an atom into its components. The components are protons and neutrons. Energy is applied to break the nucleus.

Knot is a measure of the speed of ship.

In an explosion, an internal impulse acts in order to propel the parts of a system (often a single object) into a variety of directions. After the explosion, the individual parts of the system (that is often a collection of fragments from the original object) have momentum. If the vector sum of all individual parts of the system could be added together to determine the total momentum after the explosion, then it should be the same as the total momentum before the explosion. Just like in collisions, total system momentum is conserved.

Solar energy is converted into chemical energy during photosynthesis.

In a water lifting electric pump, we convert electrical energy into potential energy.

In dealing with a coil spring the spring constant will depend on the stiffness of the spring material, the thickness of the wire from which the spring is wound and, diameter of the turns of the coil, the number of turns per unit length and the overall length of the spring.