Angular velocity and normal force for a rotating mass on a table

[bahramm]

Hi guys. I need some help to solve this question.

(a) A body of mass m kg is attached to a point by string of length
1.25 m. If the mass is rotating in a horizontal circle 0.75 m below the
point of attachment, calculate its angular velocity.

(b) If the mass rotates on a table, calculate the force on the table when
the speed of rotation is 25 rpm and the mass is 6 kg.

 

[Dweirdo]

Where Is your attempt?

 

[bahramm]

I got part a) w^2=g/h w=3.61 rad s^-1
part b ?

 

[Dweirdo]

find the the angular velocity from "the speed of rotation is 25 rpm" if i understand it correctly they gave You the frequency(convert to 1/sec) no problems getting W.
then you can find the H,and the angle the sting is spread.
find the tension(first horizontal component) than find the vertical component, and the rest is easy.
good luck I'm off now.