Can Coriolis Force affect the path of a football?

With football fresh on our minds, this week’s weather question is: Can Coriolis Force affect the path of a football?

The short answer is yes.

When a football player kicks a field goal in a north-south facing stadium, the ball will move to the right by half an inch or less.

This is because the Coriolis Force causes objects to deflect to the right in the northern hemisphere and to the left in the southern hemisphere, all because the rotation of earth!

It has a greater effect on larger objects, moving over long distances (like planes) but still has a small effect on a football.

We can figure out how much effect through the Coriolis equation (-2mΩ•v: m=mass, Ω=angular momentum, v=velocity) and a lot of math.

First you need to know how good your kicker is – how fast he can get that ball to move and at which angle.
The mass of your object – in this case the football.
You also need to know the latitude of the stadium (the closer you are to the poles – the stronger the deflection).
And the rotation of earth.
Then you can calculate the horizontal deflection.

In other words, you can figure out how much that football is going to deflect to the right once it’s kicked, and I’ll tell you – it’s not enough to excuse a missed field goal.

It’s also not enough to affect the rotation of a toilet flush.

Ever heard that if you flush a toilet in Australia the water will move the opposite direction?

It’s a myth. The design of toilets as well as the small volume of the water prevent the Coriolis Force from having any effect.

But for larger bodies of water – like oceans – the Coriolis Force plays a significant role – affecting how ocean currents, cyclones and hurricanes spin.

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