Finding sphere density falling in oil with drag force

[abs123456]

Homework Statement

A small sphere (diameter = 10 mm) is left to fall in a fluid (oil, SAEIOW) at 200 degrees
with a constant velocity of 50 mm/s..

The Following data is available:
- For SAEIOW oil at 20 degrees: p = 920 kg/m3, μ = 0.1 Pa.s

a) The drag force on the sphere
b) The density of the sphere.

Homework Equations

Cd = 24/Re^0.645

The Attempt at a Solution

a) I managed to do the first part, by using Cs in the equation F= Cd/0.5 x rho x U^2 x A

And i got 225N..

b) However i am not too sure about doing part b... if i equate the drag force to the weight it gives me
the wrong answer for density.. This part is a 13 mark question too..

 

[SteamKing]

I think you have an error in the drag force equation.
F = Cd * 0.5 * rho * A * U^2