Solução Do Halliday 8.ed.vol.1. Cap.5 - Ch05 - P087

Transcript

87. (a) Intuition readily leads to the conclusion that the heavier block should be the hanging one, for largest acceleration. The force that “drives” the system into motion is the weight of the hanging block (gravity acting on the block on the table has no effect on the dynamics, so long as we ignore friction). Thus, m = 4.0 kg. The acceleration of the system and the tension in the cord can be readily obtained by solving mg − T = ma T = Ma. (b) The acceleration is given by § m · 2 a = ¨ ¸ g = 6.5 m/s . + m M © ¹ (c) The tension is § Mm · T = Ma = ¨ ¸ g = 13 N. ©m + M ¹