Physics
posted by tim .
A bob of mass = 0.250 is suspended from a fixed point with a massless string of length = 23.0 . You will investigate the motion in which the string traces a conical surface with halfangle = 25.0.
What tangential speed must the bob have so that it moves in a horizontal circle with the string making an angle 25.0 with the vertical?
Im setting it up right but keep getting the wrong answer

The radius of the circle comes from trig:
radius=length*tangent25=23*tan25
but centripetal acceleration must equal the force of gravity pushing the bob inward, so
v^2/r=g*sin25
solve for v.