Question

If test pilot ace dimmer were sitting in his jet on the runway, his weight (supporting force) would be 600 n. when he is flying an upside down loop of radius 1000 m (1 km) at a speed of 200 m/s, with what force does his seat press on him? (remember, he is upside down.) the acceleration due to gravity is g = 10 m/s2

Answer 1

His weight is down (away from the seat) while the centripetal force is up (onto the seat). We are given the weight, so it is only the centripetal that must be determined. We can determine his mass from the supporting force: F = ma implies m = F/a = 600/10 = 60 kg. Now the centripetal force is Fc = mv^2 / r = (60*200^2)/1000 = 2400 n. Thus, subtracting off the weight (since it is directed down), the force of the seat pressing on him is Fnet = 2400 - 600 = 1800 newtons.