Two point masses are fixed on a thin rod that lies along the x-axis
PHYSICS · Multi-part · AP · Physics 1: Algebra-based · Force and Translational Dynamics · Force and Translational Dynamics
Problem
Two point masses are fixed on a thin rod that lies along the x-axis. A 1.5 kg mass is at x = 0.00 m, and a 0.75 kg mass is at x = 0.40 m. A third point mass of unknown value m_x is to be placed at x = 0.80 m such that the center of mass of the three-mass system is located at x = 0.50 m.
(1) Determine the value of the unknown mass m_x required to place the center of mass at x = 0.50 m. Show all steps in your calculation and state the result with units.
(2) If the mass m_x you found in part (a) is doubled while its position remains at x = 0.80 m, calculate the new x-coordinate of the center of mass.
(3) Compare the direction and magnitude of the center-of-mass shift that occurs when m_x is doubled. Explain why the center of mass moves the way it does.