Trig/Pre Calc Problem?

you're basically trying to find the arc distance

so the circle (if the wiper kept moving in a circle) has a radius of 48cm

so find the circumference of the circle 2(pi)r = 301.44

so the 12 degrees is out of 360 degrees, or 30 percent of the circumference (12/360)

so its moving 3.333% of the 301.44cm circumference or 10.048cm (.0333*301.44)

now, it moves 10.048cm per second

essentially, think of this problem as a unit circle, being that 48 cm is the radius of the wiperblade.

if it has an angular speed of 12 degrees/sec, then it's linear speed = 12*pi/180 = 6/90 = 2/30 = 1/15PI

s=rtheta; s=48cm*1/15PI which is 48*1/15 *3.14159...... = 10.048.

Linear velocity = radius x angular velocity (in radians/sec)

Conver 12deg/sec to radians/sec: (12 deg/sec)(pi radians/180 degrees) = pi/15

So the linear velocity is (48cm)(pi/15 radians/sec) = 48pi/15 = 10.053 cm/sec

(radians are a name for a dimensionless quantity; remember, they are a ratio of length/length)

I'm having some trouble with graphing an equation. I need to find some points on the graph so I can sketch it. I know the shape of the graph, I just need the points. My calculator's screws up these :(

use the relation s=r*theeta where theeta is in radians.