A car with tires of radius 0.25 m come to a stop from 28.78 m/s (100 km/hr) in 50.0 m without any slipping of tires. Find: (a) the angular acceleration of the wheels; (b) number of revolutions made while coming to rest.

Respuesta :

Answer:

The answer is below

Explanation:

a) Using the formula:

[tex]\omega^2=\omega_o^2+2\alpha \theta\\\\\omega=final\ angular\ velocity,\omega_o=initial\ anglular\ velocity,\alpha= angular\ acceleration,\\\theta=angular\ distance\\\\Given\ that:\\\\initial\ velocity(u)=28.78m/s,distance(s)=50\ m,radius(r)=0.25\ m,\\final/ velocity(v)=0(stop)\\\\\omega=v/r=\frac{28.78m/s}{0.25m} =115.12\ rad/s,\omega_o=0,\theta=s/r=\frac{50\ m}{0.25\ m}=200\ rad\\ \\\omega^2=\omega_o^2+2\alpha \theta\\\\115.12^2=0^2+2\alpha(200)\\\\2\alpha(200)=13252.6144\\\\\alpha=33.13\ rad/s^2[/tex]

b)

[tex]\theta=200\ rad=200\ rad*\frac{1\ rev}{2\pi\ rad}=31.83\ rev[/tex]