1. A towing force of 15 N is measured on a 1:40 scale model of a ship in a water channel. What velocity should be used to simulate a prototype speed of 10 m=s? What would be the predicted force on the ship at that speed?

2. A 1:20 scale model of an aircraft is studied in a 20-C supersonic wind tunnel at sea level. If a lift of 20 N ata speed of 250 m=s is measured in the wind tunnel, what velocity and lift does that simulate for the prototype? Assume the prototype is at

(a) sea level,

(b) 3000 m, and

(c) 10 000 m.