Energy, machines and the built world
Basic Technology · BECE · JSS (BECE)
What you need to know
- A simple machine makes work easier: lever, pulley, inclined plane, screw, wheel and axle, wedge.
- MA (mechanical advantage) = load / effort. VR (velocity ratio) = distance effort moves / distance load moves.
- Electricity: current is flow of charge; voltage is the push; resistance opposes. V = IR.
- A fuse melts when current is too high, breaking the circuit. Never replace a fuse with foil.
- Buildings: foundation, wall, roof. A lintel sits over a door or window to carry the load.
- Maintenance is cheaper than replacement. Oil moving parts; keep tools dry; report a crack in a wall.
The mistake to avoid
A fuse protects the cable and the house, not “the appliance’s feelings”. The rating must match the circuit.