Question

A plane is flying a circular path at a speed of 55.0 m/ s, with a radius of 18.3 m. The centripetal force needed to maintain this motion is 3000 N. What is the plane's mass?

Answer 1

The plane has a centripetal acceleration a of

a = v ²/r

where v is the plane's tangential speed and r is the radius of the circle. By Newton's second law,

F = mv ²/r

Solve for the mass m :

m = Fr/v ² = (3000 N) (18.3 m) / (55.0 m/s)² ≈ 18.1 kg