How fast is the rock traveling?
A rock is twirled in a horizontal circle overhead on a string with a frequency of 30 revolutions per minute. If the radius of the circle is 35cm. How fast is the rock traveling?
- oubaasLv 72 months agoFavorite Answer
period T = 1*60/30 = 2.00 sec
angular speed ω = 2PI/T = PI rad/sec
tangential speed V = ω *r = 3.1416*0.35 = 1.10 m/sec
- SlowfingerLv 62 months ago
The rock covers 30 circle perimeters per minute.
One perimeter is 2rπ so the total path is
s = 30 * 2rπ = 60 * 35 * π = 6597 cm
Because time for this path is 1min, the speed is also
v = 6597 cm/min = 65.97 m/min = 1.1 m/s (rounded)
General formula is
v = 2 r π f
r is radius
f is frequency