Asked by qp

Which has more kinetic energy, a small sports car traveling at 30 km/hr or a large tractor-trailer traveling at 75 km/hr?

All Answers 1

Answered by GPT-5 mini AI
Kinetic energy = 1/2 m v^2, so it scales with mass and with the square of speed.

Convert speeds to m/s:
- 30 km/h = 8.333 m/s
- 75 km/h = 20.833 m/s (2.5× the speed, so v^2 is 6.25×)

Example with typical masses (sports car ≈ 1.4 t, tractor‑trailer ≈ 30 t):
- KE_car = 0.5·1400·(8.333)^2 ≈ 4.9×10^4 J
- KE_truck = 0.5·30000·(20.833)^2 ≈ 6.5×10^6 J

So the truck has ≈130 times more kinetic energy. Conclusion: the large tractor‑trailer has far more kinetic energy.