Tag Archives: ODE Function

Falling Faster

Posted on March 26, 2015 by dougaj4

A recent paper by  Alexander Klotz of McGill University, Montreal, has stirred a bit of interest in the pop-science press.  The paper looks at the old question of the time taken to fall through a hole passing through the centre … Continue reading →

Posted in Excel, Maths, Newton | Tagged , , | 4 Comments

The hole through the middle of the Earth – filled with air

Posted on August 13, 2010 by dougaj4

Three air molecules go into a hole,  Well, I say three; could have been four or five.  Could have been nine or ten, doesn’t matter. Could have been fifteen, twenty – fifty. Round it up. Hundred. Let’s go mad, eh … Continue reading →

Posted in AlgLib, Differential Equations, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , , | 4 Comments

The hole through the middle of the Earth – moved to the Equator

Posted on August 2, 2010 by dougaj4

Previous posts in this series assumed that the hole went from pole to pole, and ignored such complications as tidal effects and wobbles of the axis of rotation.  In this post we will examine the effect of moving the hole … Continue reading →

Posted in Differential Equations, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , | 2 Comments

The hole through the middle of the Earth – revised transit time

Posted on July 8, 2010 by dougaj4

In the previous post in this series I produced a table of acceleration due to gravity against depth from surface, based on the four layers of the Earth (Crust, Mantle, Outer Core, Inner Core), assuming a constant density for each layer.  … Continue reading →

Posted in Differential Equations, Excel, Newton, UDFs, VBA | Tagged , , , , | 3 Comments