A car is travelling at a typical speed and makes an emergency stop to avoid hitting a hazard 25m ahead. Estimate the braking force needed to produce this deceleratoin.

V² - u² = 2as final velocity² - initial velocity² = 2 × acceleration × distance v ≈ 25 m/s m ≈ 1000 kg a = (v² - u²) ÷ 2s > (0² - 25²) ÷ (2 × 25) = -12.5 i) F = ma > F = 1000 × 12.5 = 12,500 N So the force is ≈ 12,500 N