Week3 Quiz 3

#$&*

course mth173

If a sand pile 2.7 meters high has a mass of 8660.521 kg, then what would we expect to be the mass of a geometrically similar sand pile 6.7 meters high?

8660.521/2.7 = x / 6.7

8660.521/2.7*6.7 = roughly 21,490.9kg.

This is about 3207.6 kg/m

v = k y

v = 3207.6y

If there are 1.5309 billion grains of sand exposed on the surface of the first sand pile, how many grains of sand we expect to be exposed on the surface of the second?

Using the derivative from the class notes 5 or 6, y` = .006x^2, we can plug in the 1,530,900,000 for x to find how many grains of sand are in the second pile.

@&

You haven't established how .006 is an appropriate proportionality constant for this situation. You need to start with the proportionality, the derive the appropriate relationship for the differential.

*@

,006(1,530,900,000)^2 = Approximately 14,061,928,860,000,000 grains of sand will make up the second pile.

@&

You aren't basing your work on the correct proportionalities. Review the associated Modeling Project and Class Notes, with which you do indicate some familiarity, then please resubmit this exercise.

*@