# Rotating object: Finding Tension and Vtheta

1. Homework Statement
A string with 2kg mass m on the end is connected to a bar that rotates at a constant rate (theta dot). The string makes a constant angle beta, = 60 degrees relative to the horizontal plane. Find theta dot and the tension force in the string.

2. Homework Equations

3. The Attempt at a Solution

I realize this may be very difficult to understand without a picture, but the rotation is in the x y direction I suppose and gravity is acting downward in the Z direction. I'm not really sure how to go about this problem. There's a specific velocity that will give the angle relative to the x axis the 60 degrees but I'm quite stuck, any help would be great.

Related Introductory Physics Homework Help News on Phys.org
Maybe this is right?

Ok so after fighting through it again, I realized what might work...

F(z) = 0; Tcos(30) - 2kg*9.81 = 0: T = 22 N

F(n) = ma(n); 22sin(30) = 2(v^2/1.57)

I realized I also forgot to mention the p value: 1.57

PhanthomJay
Homework Helper
Gold Member
Ok so after fighting through it again, I realized what might work...

F(z) = 0; Tcos(30) - 2kg*9.81 = 0: T = 22 N

F(n) = ma(n); 22sin(30) = 2(v^2/1.57)

I realized I also forgot to mention the p value: 1.57
Looks good so far. The solution of the 2nd equation will give you 'v'. After determining what 'v' represents, you must now determine theta dot.