# Physics

## Electromagnetic Spectrum

The electromagnetic spectrum

## Electromagnetic spectrum calculation practice problems

Calculate the energy carried by a photon with a wavelength of 13 mm.

Give your answer in electron Volts to 3 significant figures with the most appropriate metric prefix.

## Features of a wave

A wave is a movement or oscillation that spreads from a defined point, moving energy as it progresses.

## Wave Interference

Anyone who as watched the surface of a swimming pool has observed wave

## Gravitational Acceleration

We all understand that if we hold something up in the air and then let go, it will fall to the ground. Things fall because of gravity. Gravity is an attractive force between all things that have mass*.  It is one of the fundamental forces of nature. Gravity causes objects with mass to accelerate towards each other. The rate of acceleration depends on the mass of the objects and their proximity. The more mass an object contains, the more it will attract other objects. The closer an object is to another the greater the attraction between them will be.

## Buoyancy

When asked why do some things float and others sink, the first thing that comes to many people's minds is the weight* of each item. While weight*, or more properly, mass* does play a role, it is not the only factor. If it were, we could not explain how a giant ocean liner floats while a small pebble sinks. Mass matters, but there is more to it.