When a jet plane flying at 300 m/s is at the very top of its trajectory, the apparent weight of a passenger is one half of other actual weight. Find the radius of curvature R of the flight path at this point. Use g = 10 m/s$^2$
- A. 22 km
- B. 18 km
- C. 30 km
- D. 16 km
Answer: B. 18 km
Explanation: Assuming a vertical curve (hump), $mg - N = mv²/R$. Apparent weight $N = mg/2$. $mg - mg/2 = mv²/R \implies g/2 = v²/R \implies R = 2v^2/g = 2(300^2)/10 = 18000$ m.