Find height of ball rotating in cone without falling down?

[isukatphysics69]

Homework Statement

Homework Equations

f=ma
v^2/r

The Attempt at a Solution

I am confused about this question because i am not given an angle theta for the normal force on the ball.
My x component has only the normal force, my y component has only the gravitational force.
I set my y component to 0 (because the ball would be going neither up or down) and just get -mg = 0
So i am confused here on what to do. Need a hint

 

[isukatphysics69]

ok i figured it out, i had to take the tan inverse to find the angle. i didn't think it through enough so the height was .15meters, i still do not know why i am only getting partial credit (0.90/1.00) for the top question

 

[isukatphysics69]

Ok i actually figured out the top one too i will mark solved now

 

[tnich]

ok i figured it out, i had to take the tan inverse to find the angle. i didn't think it through enough so the height was .15meters, i still do not know why i am only getting partial credit (0.90/1.00) for the top question

You have the correct answer for the second part. I think there is something wrong in the problem statement for the first part. Notice that it says the height is .5m and the speed is 1.2m/s. This is inconsistent with the answer for the second part.