Coriolis Acceleration

Tuesday 1:30pm-2:40pm CC Building Circadian
Share-a-thon Part of Tuesday


Martin Farley, University of North Carolina at Pembroke


The activity is basically one page and I can present the activity and discuss its completion at the Rendezvous Share-A-Thon.


This is an activity intended to get Oceanography students to look and understand components of an equation. I always do this when I see equations:
Which terms are constants? Do you know the constant's value (if not, can you figure it out?)
Do some variables change within limits? If so, how does this constrain the output of the equation?

Coriolis Acceleration = 2 Ω v sin φ where Ω = Earth's angular rotation (radians/unit time),
v = linear velocity of the object (metric), and φ = latitude (in degrees)
(it's also a vector equation)

Ω is a constant, but who has that memorized? Students can calculate it, however.

The sin φ obviously varies within limits (from 0 to 1 from equator to pole) thus constraining the acceleration.

After students figure this out, I have them calculate Coriolis acceleration at the latitude of UNC-Pembroke and compare it to the acceleration due to gravity for context on magnitude (although this is in a different direction) to see its importance for objects like speeding cars. I finally ask them to consider phenomena in which this acceleration would be important.


This is an activity in my Oceanography course, whose official target audience is our departmental majors and science education majors, but which attracts students from other science majors. This course is highly hands-on and emphasizes activities that provide practice in straightforward calculations for key oceanographic concepts.

Why It Works

This introduces students to the importance of looking at equations before you start punching numbers into a calculator so you can understand the variation and magnitude of the results. They also learn about the importance of context for any numerical result.

My students also need all the practice they can get in simple calculations, unit conversions (e.g., 24 hours to seconds for angular rotation), and putting the calculation results into context.