What is the weight that will balance the object Q?

Poster has been reminded that the use of the HH Template and showing work is not optional
Here is diagram for Tower Crane.

The Rack weight P=700kN, and the maximum load capacity for this crane is W=200kN. The long beam length is 12 metres, and the balance object weighs Q. The short beam length is 6 metres. What is the weight of Q to keep the crane's balance at all situation?


Why should it be like that?
There are 2 situations
Full load, W=200 kN. let ##Q_{min}## stands for the minimum weight requirement of Q.

$$\sum m_B(F)=0, (6+2)Q_{min} + 2P - (12-2) W=0, N_A=0$$

No load, W=0 kN. let ##Q_{max}## stands for the maximum weight requirement of Q

$$\sum m_A(F)=0, (6-2)Q_{max} - 2P =0, N_B=0$$

The Physics Forums Way

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving