Air is pumped into a bicycle tire. The 18 moles of air initially in the tire have a gauge pressure of 5 atm. How many moles of air must be pumped into the tire in order to raise the gauge pressure to 10 atm?

Suppose a wheel with a tire mounted on it is rotating at the constant rate of 2.15 times a second. a tack is stuck in the tire at a distance of 0.373 m from the rotation axis. noting that for every rotation the tack travels one circumference (a) find the tack's tangential speed. (b) what is the tacks radial acceleration?