Determine the angular velocity of the Wheel

[Northbysouth]

Homework Statement

The cart has a velocity v_c = 3.4 ft/sec to the right. Determine the angular speed N (positive if counterclockwise, negative if clockwise) of the wheel so that point A on the top of the rim has a velocity (a) equal to 3.4 ft/sec to the left, (b) equal to zero, and (c) equal to 6.8 ft/sec to the right.

I have attached an image of the question

Homework Equations

The Attempt at a Solution

v_A = v_O + v_A/O

v_O = -3.4i

v = wXr

r = 11.6j

For part a)

-3.4i = 3.4i + wX<11.6j>

Solving for w gives me

w = 6.8/11.6 k rad/sec

Which is equivalent to

w = 5.597 rev/min

I don't think this is right and I can't see what's wrong with what I've done.

Advice would be greatly appreciated.

 

[Northbysouth]

Nevermind, I found my mistake. I forgot to convert the 11.6" to feet.