In 1964, after the 1250-kg jet-powered car Spirit of America lost its parachute
ID: 2179096 • Letter: I
Question
In 1964, after the 1250-kg jet-powered car Spirit of America lost its parachute and went out of control during a run at Bonneville Salt Flats, Utah, it left skid marks about 8.0 km long. (This earned a place in the Guinness Book of World Records for longest skid marks.)1) (a) If the car was moving initially at a speed of about 849.0 km/h, and was still going at about 314.0 km/h when it crashed into a brine pond, estimate the coefficient of kinetic friction ? k.
(b) What was the kinetic energy of the car 30.0 s after the skid began?
Explanation / Answer
v^2-u^2=2*a*s u=235.83m/s v=87.22m/s a=-mu*g s=8000m a=-3m/s^2 mu=0.305 v=u+a*t=145.83m/s E=0.5*1250*v^2=13.3*10^6j