# Tag Archives: ODE Function

## Falling Faster

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 | | 4 Comments

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

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 | | 4 Comments

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

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 | | 2 Comments

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

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 | | 3 Comments