Question

A person with mass m1 = 80 kg stands at the left end of a uniform beam with mass m2 = 100 kg and a length L = 4.0 m. Another person with mass m3 = 110 kg stands on the far right end of the beam and holds a medicine ball with mass m4 = 10 kg (assume that the medicine ball is at the far right end of the beam as well). Let the origin of our coordinate system be the left end of the original position of the beam as shown in the drawing. Assume there is no friction between the beam and floor.

A) What is the initial location of the center of mass of the system?

B) What is the initial velocity of the center of mass of the system?

C) The ball is thrown to the left end of the beam. Where is the center of mass now?

D) The two people now switch places on the beam. Where is the center of mass now?

E) Both people walk to the center of the beam. At what x-position do they end up?

please please help me

Answer 1