8. A 1250 kg car is driving on a flat road around a turn with a 90-meter radius of curvature. When the road is dry, the coefficients of friction between the road and the tires are μs = 0.75 and μk = 0.45. What is the maximum speed a car can enter this turn without losing traction?
a. 662.2
b. 18.20
c. 25.7
d. 19.93
9. You are riding a roller coaster going around a vertical loop, on the inside of the loop. If the loop has a radius of 40 meters, how fast must the cart be moving in order for you to feel five times as heavy at the bottom of the loop?
a. 1570
b. 39.62
c. 48.52
d. 44.30