calculations

calculations

1.a) Photosynthesis is estimated to produce 370.0 g (dry weight) of plant matter per square meter, 50% of which is carbon. The photosynthetic reaction can be represented as:
6CO2 + 6H2O -> C6H12O6 + 6O2
Of the glucose produced, 30.0% is used by the plant to fuel respiration; the rest is converted to plant matter. Calculate the total moles of glucose produced annually in our reference 1000 square meter area.

part a (g/m2)x(m2)x fraction C
part b convert C to fixed carbon. calculate mol fixed C. calculate mol glucose

2. If world energy consumption continues to rise at the present annual rate of 2.2%, how long will it take to double (expressed in years

Q(t) = Q0 expt (kt)

3. Should you install a solar water heater? The average home has a 200 liter (50-60 gallon) hot-water tank, which is effectively drained and replenished three times per day. Assume that the entering tap water is 20 degrees C and is heated to 55 degrees C. Given an average energy from sunlight of 1.53 kJ/cm2 per day, how large would the collection area (in m2 of a solar water heater need to be if its efficiency is 20%? Assume that the price of a solar collector is $375/m2. How much would it cost to install this hot water system???

Calculate energy required to heat 1 mL of water. Convert this to tank volume. area=heat required/(solar heat/area)/eff. Installation cost = area x solar collector cost.
———————————————————————————————
Sources:
T.S. Glickman and M. Gough, editors, Readings in Risk (Resources for the Future, Washington, DC, 1990) – Lessons*8G11

R. Muller, Energy for Future Presidents (Norton, Philadelphia, 2012) – (E)*IV,*II

L. Weinstein and J.A. Adam, Guesstimation(Princeton, Princeton, 2008) – Ch*6,*9