What information do you need to calculate the pressure (weight) ...

[CBme]

What information do you need to calculate the pressure (weight) of a column of rock? Calculate the pressure at the base of oceanic and continental crust for columns of rock that are one square meter in area at the surface.
 
  What will be an ideal response?

Question 2

What is the observed range of mountain uplift rates? How does this range in values compare with the speed of plate motion?
 
  What will be an ideal response?

[jessicaduplan]

Answer to Question 1

In order to calculate the pressure (weight) of a column of rock you need to know the volume of the column, the density of the rock, and the acceleration of gravity.
Oceanic crust
Volume = 7,000 m3
Density = 2.7 g/cm3 = 2,700 kg/m3
Gravity = 9.81 m/s2
Weight = 7,000 m3 x 2,700 kg/m3 x 9.81 m/s2 = 185,409,000 Newtons or 41,681,600 lbs

Continental crust
Volume = 35,000 m3
Density = 3.0 g/cm3 = 3,000 kg/m3
Gravity = 9.81 m/s2
weight = 35,000 m3 x 3,000 kg/m3 x 9.81 m/s2 = 1,030,050,000 Newtons or 231,564,450 lbs

Answer to Question 2

The range of uplift rates is 3 to 10 mm per year which is about 10 times slower than plate motions of about 1 to 10 cm per year.