What is physics?
Physics is the science that studies matter, energy and how they interact. It explains why a ball falls, how a radio works and why the sky has stars. Physics is behind phones, vehicles, hospitals and power stations.
| Branch | It studies | Everyday example |
|---|---|---|
| Mechanics | forces and motion | a bicycle slowing down |
| Heat | temperature and energy transfer | boiling water |
| Light | how light travels | a mirror |
| Sound | vibrations that we hear | a drum |
| Electricity and magnetism | charges, currents and magnets | a torch, a compass |
| Atomic physics | the structure of atoms | X-rays in hospitals |
How physicists work
Physicists follow the scientific method: observe, ask a question, suggest an answer (a hypothesis), test it with an experiment, then decide whether the results support it.
Try itA falling stone experiment
Change the height and see how long a stone takes to fall. This is what you would measure in the experiment above (air resistance is ignored). The time follows with m/s².
Key terms
- Physics
- The science of matter, energy and their interactions.
- Hypothesis
- A testable suggestion that might explain an observation.
- Experiment
- A test carried out under controlled conditions.
Summary
- Physics studies matter and energy; its branches include mechanics, heat, light, sound, electricity and atomic physics.
- The scientific method: observe, hypothesise, experiment, analyse, conclude.
- Change one thing at a time in a fair test.