Answer to Question #125747 in Classical Mechanics for Hussain Ousman Darboe

Question

Two bicycles tyres are set rolling with the same initial speed of 3.5m/s on a long straight road and the distance each travels before its speed is reduced by half is measured. One tyre is inflated to a pressure of 40 psi and goes 18.1m; the other is at 105 psi and goes 92.9m, what is the coefficient of rolling friction for each? Assume that the net horizontal force is due to rolling friction only.

Answer 1

$$(0.5v)^2-v^2=-2\mu_1 gs$$

$$0.75(3.5)^2=2(9.8)(18.1)\mu _1\\\mu _1=0.026$$

$$(0.5v)^2-v^2=-2\mu_2 gd$$

$$0.75(3.5)^2=2(9.8)(92.9)\mu _2\\\mu _2=0.005$$