Question

A 950-kg race car can drive around an unbanked turn at a maximum speed of 44 m/s without slipping. The turn has a radius of 140 m. Air flowing over the car's wing exerts a downward-pointing force (called the downforce) of 12000 N on the car. (a) What is the coefficient of static friction between the track and the car's tires? (b) What would be the maximum speed if no downforce acted on the car?

Refer to Interactive Solution 6.59 for a review of the approach taken in problems such as this one. A 61.0-kg person jumps from rest off a 4.80-m-high tower straight down into the water. Neglect air resistance during the descent. She comes to rest 1.40 m under the surface of the water. Determine the magnitude of the average force that the water exerts on the diver. This force is non-conservative.

Answer 1

mv 2 0 uling+F) : mu r cas le 9500 (44,² ТЧо (as *9.8+ 12000) 13137.1429 и 7 21310 l- 0. 616 (b) rung = m my² Va 0.616 x 950 x 9.8 x 140 gro va 29.08 ms 9.699 mys 2 Vis 2x9.8 x 4.8 Ve : 0 2 (9.699) a = ==33.6 m/s² 2x1140 2049.6 N ch 61 X 33.6 7 15