Before 1960, people believed that the maximum attainable coefficient of static f

Question

Before 1960, people believed that the maximum attainable coefficient of static friction for an automobile tire on a roadway was ?s = 1. Around 1962, three companies independently developed racing tires with coefficients of 1.6. This problem shows that tires have improved further since then. The shortest time interval in which a piston-engine car initially at rest has covered a distance of one-quarter mile is about 4.43 s.

Before 1960, people believed that the maximum attainable coefficient of static friction for an automobile tire on a roadway was ?s = 1. Around 1962, three companies independently developed racing tires with coefficients of 1.6. This problem shows that tires have improved further since then. The shortest time interval in which a piston-engine car initially at rest has covered a distance of one-quarter mile is about 4.43 s. Assume the car's rear wheels lift the front wheels off the pavement as shown in the figure above. What minimum value of ?s is necessary to achieve the record time? Suppose the driver were able to increase his or her engine power, keeping other things equal. How would this change affect the elapsed time?

Explanation / Answer

s = ut + 1/2 a*t 2

initally at rest u = 0

1 mile = 1609.34 m

402.336 = 0 + 1/2 * a * 4.43 ^2

a = 2 * 402.336 / 4.43^2 = 41 m/s2

ma = mg * ?

v = u +at = 41 * 4.43 = 181.63

change in kinetic energy = work done

1/2 * m*v^2 = u * m * g * s

u = 1/2 * v^2 / (g * s) = 4.183

if the driver were able to change the enginee power and keeping other things as it is it will start rotating the wheel with greter acceleration force and finaly may the time decrease

Related Questions

Navigate

• Browse (All)
• Browse B
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.