Question

 A 1200-kg SUV is moving along a straight highway at 12.0 m/s. Another car, with mass 1800 kg and speed 20.0 m/s, has its center of mass 40.0 m ahead of the center of mass of the SUV (Figure 1).

 Part A

 Find the position of the center of mass of the system consisting of the two cars.

 Part B

 Find the magnitude of the system's total momentum, by using the given data.

 Part C

 Find the speed of the system's center of mass.

 Part D

 Find the system's total momentum, by using the speed of the center of mass.

 Part E

 Compare your results of parts B and D.

•  P1 > P2

•  P1 < P2

•  P1 = P2

Answer 1

  a) x = 1800kg * 40m / (1800+1200)kg = 24 m ahead of the s.w.
b) p = 1800kg * 20m/s + 1200kg * 12m/s = 50 400 kg·m/s
c) v = 50400kg·m/s / 3000kg = 16.8 m/s
d) p = Mv = 3000kg * 16.8m/s = 50400 kg·m/s
e) same!