Making of the jib crane & calculations

[speko1]

Homework Statement

Need to do calculations for the jib. The jib is 600 mm long and 40 mm wide. It is attached to a base at the bottom with a pin. The cable is going through from the motor, and at the top there is a pulley. We have to lift 2 kg of weight with a motor.

The jib is very stable, and I am sure it will do its job, but not sure how to calculate all the forces that are acting on the jib. There is a force of 20 N(2kg) which is required to be lifted. Now, I am unsure, whether we have to calculate all the forces in the jib, or just the ones at the top and bottom part.

Also, the jib will be connected to a cable at around 200 mm when going from the top downwards, and once it is at 60 degrees it has to lift required weight of 2 kg.

Homework Equations

The Attempt at a Solution

first question:Just need some suggestions whether I should calculate all the forces acting on the jib or just partialy.
second: I am guessing that there is only one moment, and that is at the part where the jib is connected to the base with a pin, point A. As i said above, the jib will also be connected to another cable at 400 mm, measuring from the bottom. Does it mean there will be a moment at point B as well.

 

[haruspex]

whether I should calculate all the forces acting on the jib or just partialy.

Depends what you are trying to determine. Your stated task is

how to calculate all the forces that are acting on the jib

guessing that there is only one moment, and that is at the part where the jib is connected to the base with a pin, point A

It is a pin, so freely jointed; no torque exerted there.
Torque is relative to a chosen axis. Which axis are you choosing? What forces on the jib do not pass through that axis?