Assignment 3 b (applications)

1. X liters of a 5% salt solution are added to 10 liters of 2% salt solution. Find the end concentration as a function of X. (Hint: how much solution to you end up with? How much salt does it contain?)

2. A $10000 copy machine is depreciated on a 15 year, straight-line schedule. Give the book value as a function of time. (Hint: value(t=0) = 10000, value(t=15)=0.)

3. The position in meters of an object moving straight up and down under gravity is given by s(t) = -4.9*t^2 + v0*t + s0, where v0 is the initial velocity in meters/second, s0 is the initial height in meters, and t is time is seconds. An object is shot up from ground level with an initial velocity of 50 m/s. Find the position at 5 seconds.

4. The per capita growth rate of a species of bacteria as a function of food concentration is given by the curve below. At approximately what food concentration is the per capita growth rate = 1?