[填空题]
Three identical cylinduje0fg0 w d jg35ze;;g2c6egf ers c.j-w70iwb 0f 0v nopwsit inside a cup. Their radius of each is 5 cm and their centres of mass are marked in the diagram. The lines connecting the v pbw f0w.oi0c7n0-jwcentres of the masses pass through the contact points between the cylinders.
1.Draw and label the free-body diagram for the cylinder $M_3$ 2.1For analysis purposes, the three cylinders can at times be considered as a single object consisting of the mass of the all cylinders. Explain why this simplification may be useful.
2.2The reaction force of the ground on $M_3$ is 30N Show that the mass of each cylinder is around 1.0 kg kg
3.Determine the force that mass $M_3$ exert on $M_1$ N
