Quote:

Originally Posted by

**DanBrown100** Need help on this please folks, it has got me stumped.

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

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

Part 2.

I assume for the second part that the radius of the circle is the same as in Part 1. The table supplies the extra force needed since the tension T will be reduced. The force the ball exerts on the table is equal in magnitude to the force the table exerts on the ball (but in the opposite direction).

Following what **skeeter** gave, you then have:

$\displaystyle T_2\sin{\theta} = m\,r\,{\omega_2}^2$

$\displaystyle T_2\cos{\theta} +F_T = mg$

$\displaystyle \omega_2=60\cdot 2\pi\cdot 25$ in units of radians per second.