Add latest project and new docs.

Codecademy.md

@@ -211,6 +211,34 @@ is the passed argument and thus what is used for a result:
 Creating a spreadsheet called Applications with 10 rows.
 ```
 
+## Returning Stuff
+
+  You can return stuff like this to store for later:
+
+```
+def addfour(number, cow):
+  addedfour = number + 4
+  cat = number - 4
+  return addedfour, cat # All returned arguments must be on the same return call.
+```
+
+I'll make it add four to 456
+
+```
+yo, cow = addfour(456)
+print ("456 + 4 equals " + str(yo) )
+```
+
+```
+460
+```
+
+You can also do this with multiple arguments:
+
+```
+x_squared, y_squared = square_point(1, 3)
+```
+
 # Fun Projects
 
 Design a shop using Ex7 and Ex9 as a frame:

Codecadmey Projects/Physics-ch2.py

@@ -0,0 +1,40 @@
+train_mass = 22680
+train_acceleration = 10
+train_distance = 100
+
+bomb_mass = 1
+
+def f_to_c(f_temp):
+  c_temp = (f_temp - 32) * 5/9
+  return c_temp
+
+f100_in_celsius = f_to_c(100)
+#print(f100_in_celsius)
+
+def c_to_f(c_temp):
+  f_temp = (c_temp * (9/5) + 32)
+  return f_temp
+
+c0_in_fahrenheit = c_to_f(0)
+#print(c0_in_fahrenheit)
+
+def get_force(mass, acceleration):
+  return mass * acceleration
+
+train_force = get_force(train_mass, train_acceleration)
+
+#print(train_force)
+print("The GE train supplies " + str(train_force) + " Newtons of force.")
+
+def get_energy(mass, c = 3*10**8):
+  return mass * c*c
+
+bomb_energy = get_energy(bomb_mass)
+print("A 1kg bomb supplies " + str(bomb_energy) + " Joules")
+
+def get_work(mass, acceleration, distance):
+  return get_force(mass, acceleration) * distance
+
+train_work = get_work(train_mass, train_acceleration, train_distance)
+
+print("The GE train does " + str(train_work) + " Joules of work over " + str(train_distance) + " meters.")