# Finding The Speed Of A Train Using Basic Trigonometry.

Question: The wheel of a carriage is 3 feet in diameter and makes 3 revolutions per second; how fast is the train going?

I'm gonna walk myself through this and hopefully I get it right...

Well for starters, the radius of the wheel is 1.5 feet. So the circumference is $1.5\cdot2\cdot\pi=3\pi$ feet. The wheel has three revolutions per second. So it is moving at $9\pi$ feet per second right?

Can you guys help me out?

• Assuming no slipping, yes. This is hardly trigonometry though. – Macavity Oct 8 '15 at 6:35
• Why do you think its wrong – Archis Welankar Jan 7 '16 at 5:52