Resource 4: Examples of Physics in action
Teacher resource for planning or adapting to use with pupils
Examples of physics in action
Places to visit and examples you might see
| Place | Examples | Physics principles they use |
| Garage or workshop | Hydraulic jacks | Pressure = force/area and pressure is transmitted through a fluid (oil), so input pressure = output pressure Used as a ‘force multiplier’ |
| Brace, screwdriver | Input force x input distance from axle = output force x output distance A force multiplier | |
| Building site | Pulleys | Input force x distance it moves = output load raised x height it is lifted. A force multiplier |
| Wheelbarrows and levers | Input force x input distance from wheel axle or pivot = output force x output distance from pivot A force multiplier | |
| Kitchen or bakery | Can openers, potato chippers, nut-cracker | Examples of levers as force multipliers, so small force exerted by operator on the handle produces a large force on the object: Input force x input distance from pivot = output force x output distance |
| Knives and skewers | Narrow blade edges and fine points cut into the material more easily because, for the same force, reducing the area increases the pressure | |
| Playground | Seesaw | Another lever example: a lighter person sits further out to balance a heavier person. Clockwise moment = anticlockwise moment |
| Farm/garden | Shears/secateurs/ branch cutters | Force multipliers: Input force x input distance from pivot = output force x output distance |
Some examples of force multipliers
Hydraulic jack:
You use a small force but push further to raise the large load a smaller distance.
Input pressure = output pressure because the pressure is transmitted by oil.
- narrow input piston cylinder with area A1 , small input force F1
- wider output piston cylinder with area A2, larger output force F2
- force on output piston
Levers , e.g. see-saw:
Clockwise turning force x distance from pivot = anticlockwise turning force x distance from pivot
Cutting tools e.g. secateurs, shears:
Resource 3: Everyday examples of pressure
