Q: A small ball of mass m is suspended by a light thread. When a strong wind blows horizontally, exerting a constant force F on the ball, the thread makes an angle θ to the vertical. Using the terms provided, write an equation linking m, F, g and θ.
I have not been able to work this out, I got the equation (mg/cos(θ)) = squareroot(F^2 + (mg)^2) and do not know where I went wrong.