1. When you drive a car around, the tire leaves a mono-molecular layer of rubber everywhere it goes. A typical tire lasts 50,000 miles. go look at a tire and estimate the depth of the tread (use this as the thickness of the tire tread: 0.3125 inches), and therefore the thickness of the rubber left on the road, on average, over those 50,000 miles. is that thickness reasonable to be mono-molecular?

2. Piano strings (it turns out) are characterized by a mass m, a length L, and a tension T (force). Find an expression that combines m, L, and T into a quantity with the units of frequency. Now imagine a piano string has a diameter of D = 1 mm, a length of L = 2 m, and is made of steel. What, roughly, is its mass m? And roughly what is the tension T it must have to play middle C? You might have to look up the frequency of middle C on the internet.