The torques acting on the crane boom can be computed about anaxis passing through the top of the boom. (this is the place wherethe spring scale and mass hanger connect to the boom) apply thesecond condition for equilibrium to the crane boom and derivethe resulting equation for the sum of torques about this newpoint

What equation?

exactly. This is all I was given. Possibly

SumOf t = T(exp)*length* sin(theta) - W(hang) * length * sin(phi) - W(boom) * L(exp) * sin(phi) = 0

but im not sure.

To derive the equation for the sum of torques about the point where the spring scale and mass hanger connect to the crane boom, we need to apply the second condition for equilibrium. The second condition for equilibrium states that the sum of torques acting on an object must be zero in order for it to be in rotational equilibrium.

Let's assume that there are multiple torques acting on the crane boom about this point. Each torque can be represented as the product of the force applied and the perpendicular distance to the point where the forces are applied.

If we have n torques acting on the boom, the equation for the sum of torques can be written as:

Στ = τ₁ + τ₂ + τ₃ + ... + τₙ = 0

Where τ₁, τ₂, τ₃, ..., τₙ represent the torques acting on the boom.

Since the torques are computed about an axis passing through the top of the boom, the perpendicular distance to this point for each torque will be the same. Let's assume this perpendicular distance is represented by "d".

So, the equation can be further simplified as:

Στ = τ₁ + τ₂ + τ₃ + ... + τₙ = 0

Now, when a torque is applied in the clockwise direction, it is considered negative, and when it is applied in the counterclockwise direction, it is considered positive.

To derive the resulting equation for the sum of torques about this point, you need to consider the specific forces and distances involved in your problem. The torques can come from the weights of the load, the crane arm, or any other external forces acting on the boom. You would need to determine the force vectors and the corresponding perpendicular distances, and then plug them into the equation Στ = 0.

By summing up all the torques and setting the equation equal to zero, you can solve for any unknowns or obtain the equilibrium condition for the crane boom about the given point.