A car travelling 18km/hr drives over a nail and it sticks in one of the front tires. The tire has a radius of 14 cm. Determine the height of the nail above ground 5 minutes after the car drives over the nail, assuming the tire does not go flat.
Hints: how many rotations per minute does the tire make? You need to watch the units here. Then multiply by 5 to get the number of rotations made by the tire. Now convert that to an angle in radians and use a little trig.