Problem # p031

Motion of System of Particles, 2-D
Two masses, m1 and m2, are initially at rest. Suddenly, a force P is applied to m1 as shown in the figure. As a result the two masses accelerate together to the right.

m1 = 12 kg           m2 = 16 kg
μ1,kin = 0.30 μ2,kin = 0.23
μ1,stat = 0.32 μ2,stat = 0.26
g = 9.81 m/s²



  1. Draw the F.B.D. for mass m1
  2. Draw the F.B.D. for mass m2
  3. Draw the F.B.D. for both masses as a unit.
  4. At what value of P will mass m2 be on the verge of not accelerating at the same rate as m1 ?
    (Hint : find first the maximum acceleration of m2 )