A yo-yo is thrown downward with a rotational spin. Reaching the bottom of the string, it climbs back upward. Is the rotational direction reversed at the bottom? Explain.
Answer to relevant QuestionsThe drain plug on a car’s engine has been tightened to a torque of 25 m ∙ N. If a 0.15-m-long wrench is used to change the oil, what is the minimum force needed to loosen the plug? Show that the balanced meterstick in Example 8.5 is in static rotational equilibrium about a horizontal axis through the 100-cm end of the stick. In doing physical therapy for an injured knee joint, a person raises a 5.0-kg weighted boot as shown in Fig. 8.39. Compute the torque due to the boot for each position shown. If the cord attached to the vertical wall in Fig. 8.44 were horizontal (instead of at a angle), what would the tensions in the cords be? Two masses are suspended from a pulley as shown in Fig. 8.47 (the Atwood machine revisited; see Chapter 4, Exercise 55). The pulley itself has a mass of 0.20 kg, a radius of 0.15 m, and a constant torque of due to the ...
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