Mechanics question on resolving forces

This question's confused me. How do you go about saving it?

"A concrete slab of mass m kg is being raised vertically, at a constant speed, by two cables. One of the cables is inclined at 10 degrees to the vertical and has a tension of 2800 N; the other cable has a tension of 2400N. Calculate the angle at which this cable is inclined to the vertical.

Thanks

The concrete slab is being raised at a constant speed, so there is no vertical acceleration.
That is a = 0.

Since F = ma, so F = 0, meaning the net vertical force is 0.

Force by gravity: m*(-9.8) = -9.8m
Force from cable one: 2800cos(10°)
Force from cable one: 2400cos(θ°), θ° being the angle at which this cable is inclined to the vertical

Thus, 9.8m= 2800cos(10°) + 2400cos(θ°) -------- (1)

Since the slab is being raised vertically, the net horizontal force is also zero.
2800sin(10°) = 2400sin(θ°) -------- (2)

Apparently, equation (1) is not needed to calculate θ°, but it is needed to calculate mass, m.

Hope this clears things up for you.

I meant force from cable two: 2400........

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