Math 127 Trigonometry

Question

A wheel rotates at 2880 degrees  per second. What is the angular speed (in radians per minute)?

Write your answer in terms of pi. Type pi for ππ.

ω =    radians/min

What is the linear speed (in inches/minute) of a point on the wheel 13 inches from the center?

Write your answer in terms of pi. Type pi for ππ.

v =    inches/min

Answer 1

Use dimensional analysis, by multiplying by conversion factors = 1 to change the units to what you want:

ω = 2880°/1 sec · 60 sec / 1 min · 2π rads / 360° = 960π rads / min

v = r · ω = 960π rads / min · 13 in = 12,480π in / min