I honestly don't know how to find the friction, much less frictional torque, when given things like this. 1. The problem statement, all variables and given/known data "If you lift the front wheel of a poorly maintained bicycle off the ground and then start it spinning at 0.72rev/s, friction in the bearings causes the wheel to stop in just 12s. If the moment of inertia of the wheel about its axle is 0.30kg\m2 , what is the magnitude of the frictional torque?" 2. Relevant equations I know: Στ=Iα α=Δω/Δt I=mr2 3. The attempt at a solution Like I said, I have no idea how I am supposed to use the given variables to find friction. This is an attempt I tried: α=Δω/Δt =0.72/12 =0.06m/s2 So I can now find torque with the angular acceleration: ∑τ=Iα = (0.30kg/m2)(0.06m/s2) = 0.018Nm That's a small number that I'm pretty sure isn't right. Even if it is, I don't know where to go from here to find friction. If someone could just guide me/give me equations then I'd appreciate it thanks!