A uniform metre rule is pivoted at the 34.0 cm mark, as shown.
The rule balances when a 64g mass is hung from the 4.0 cm mark.

What is the mass of the metre rule?

A man holds a 100N load stationary in his hand. The combined weight of the forearm and hand is
20N. The forearm is held horizontal, as shown.

What is the vertical force F needed in the biceps?

The diagram shows four forces applied to a circular object.

Which of the following describes the resultant force and resultant torque on the object?