Cards | 10 |

Focus | Forces and Energy |

Topics | Electromagnetic Spectrum, Force, Kinetic Energy, Magnetism, Power, Weight, Work |

The electromagnetic spectrum covers all possible wavelengths and frequencies of **radiation**. From lowest frequency (longest wavelength) to highest frequency (shortest wavelength) radiation: radio waves → microwaves → infrared waves → visible light → ultraviolet light → X-rays → gamma rays.

Force is applied to change an object's **speed** or **direction of motion**.

Kinetic energy is the energy posessed by a moving object. **Potential energy** is stored energy in a stationary object based on its location, position, shape, or state.

Simple magnets have two poles, north and south, and opposite poles attract each other (N attracts S, S attracts N). Likewise, the same pole of two magnets repel (N repels N, S repels S). The Earth has a magnetic field and North and South Poles which enables the use of a **magnetic compass** to determine direction.

Power is the rate at which work is performed or work per unit time: \(P = {w \over t}\) and is measured in **watts (W)**.

Weight is a force that describes the attraction of **gravity** on an object. Force is measured in **newtons (N)** with 1 N being the force required to impart an acceleration of 1 m/s^{2} to a mass of 1 kg.

Work is performed on an object when an applied force causes displacement along the same vector. Measured in **joules (J) **or **newton-meters (Nm)**, work is calculated by multiplying force times displacement: \(W = \vec{F}\vec{d}\)