actually
Ke = (1/2) I w^2
The average car today has a mass of 1100 kg, and when accelerating from rest, covers 0.25 miles in 15 seconds. Each rim and tire together has a diameter of 46 cm and a mass of 9.1kg. If we agree the rim and tire have the shape of a solid disk that rotates through its geometric center, what would be the kinetic energy of one of the tires, in Joules, at the end of the run?
I know KE=Iw^2
I calculated the moment of inertia to be 1.0465 kg*m
to find w, i calculated the number of revolutions for the given distance to be 278. dividing by time = 18.5rev/sec
converting to rad 116 rad/sec
so Ke= 116^2*1.0465 = 14081.704 j
am i right? i also need help with sig figs
2 answers
oops. but would the answer be correct if everthing was factored in?