General Science, Environment and Road Safety
General Science, Environment and Road Safety tests basic physics, chemistry, biology, ecology, pollution and safe road behaviour. The science is school-level, but units and definitions must be exact.
Science and environment
- SI units: force in newtons, work in joules, power in watts, pressure in pascals.
- Mass is constant; weight = mg and changes with gravity.
- Acids have pH below 7, bases above 7; pH 7 is neutral.
- Photosynthesis converts carbon dioxide and water into glucose and oxygen using sunlight and chlorophyll.
- Pollution types include air, water, soil and noise; biodiversity loss and climate change are major environmental concerns.
Road safety
- Stopping distance = reaction distance + braking distance.
- Reaction distance = speed × reaction time; braking distance grows with the square of speed.
- Helmets, seat belts, lane discipline and avoiding mobile phone use reduce risk.
Worked example
A vehicle travels at 54 km/h (15 m/s). Reaction time is 0.5 s, so reaction distance = 15 × 0.5 = 7.5 m. With μ = 0.5, braking distance = v²/(2μg) = 225/(2 × 0.5 × 9.8) ≈ 22.96 m. Total stopping distance ≈ 30.5 m.
Traps that cost marks
Confusing mass with weight, using km/h in metres-per-second formulas, and forgetting that braking distance is proportional to the square of speed are common. In road safety, do not treat reaction distance as part of braking distance.