A 75.0-kg man stands in the far end of a 50.0-kg boat 100 m from the shore, as illustrated in ▼Figure 6.19. If he walks to the other end of the 6.00-m-long boat, (a) does the CM (1) move to the right, (2) move to the left, or (3) remain stationary? Neglect friction and assume the CM of the boat is at its midpoint. (b) After walking to the other end of the boat, how far is he from the shore? (a) CONCEPTUAL REASONING. With no net external force, the acceleration of the center of mass of the manboat system is zero (Equation 6.18), and so is the total momentum by Equation 6.17 ( ) P V CM CM = = M 0 . Hence, the velocity of the center of mass of the system is zero, or the center of mass is stationary and remains so to conserve system momentum; that is, X X CMi f ( ) initial f = CM ( ) inal , so the answer is (3).

Transcribed Image Text:

-6.00 m- -100 m- FIGURE 6.19 Walking toward shore See Example 6.16 for description.