Pressure is defined as a force exerted by either a gas or a liquid per unit area. We will focus on the pressure exerted by gasses. In gasses, pressure is a measure of the force that results in particles colliding with the walls of the containter. The air exerts pressure as well. This pressure is exerted on the container from the outside. It's important to note that pressure is not a force, it exerts a force.
Temperature is how hot or how cold something is. Specifically for gasses it measures the average translational kinetic energy. In other words, the faster the atoms move the hotter the object is, or the slower the atoms move the colder the object is.
Another concept that is good to know about is heat. Heat is the energy that is transfered during the interaction of
two or more systems (systems often describe objects). When two objects of different temperatures interact they seek thermal equillibrium.
This is where heat come into play. Thermal equillibrium is when the two objects cease to exchange energy, in other words when Q=0, when
heat is no longer being transfered. For this experiment it is not incredibly important to know the formula for heat unless you didn't have
a thermometer to measure the change in temperature, but it is good for context to know about it.
By now you are probably wondering what does temperature and pressure have to do with each other. Well,
temperature and pressure are related by the ideal gas law, which is pV=nR DT. p is
pressure, V is volume, n is the amount of moles of a gas, R is the universal gas constant which has a few values
but the value that is relevant to this experiment is 0.0821 L * atm⁄mol * K,
and DT is the change in temperature.
The application of this relationship is how changes in temperature affect the pressure in a container. This is best shown in experiment with a water bottle and warm water. Click the Experiment tab to learn more.