Question

to an * - - - - - - - - 1. [1 pt) A professor of mass m = 51 kg is seated on a light harness connected to a rope and pulley system as shown. The professor's feet touch a uniform plank of mass mplank = 12 kg which is supported by a hinge at the wall. A mass M in a light bucket is suspended from the right end of the plank. The professor is a distance l = 2.60 m from the hinge; the plank has length L = 4.50 m. Answer true or false to the statements below; e.g., if the first one is true and the rest are false, enter TFFFF. i. The weight of the plank leads to a counter-clockwise torque on the plank, taken about the hinge. ii. If M>0, the right end of the plank will accelerate downward for some values of M. iii. If the plank remains horizontal, the concept of torque is not important in order to calculate the tension in the rope. iv. If the plank remains horizontal, the force of the professor on the plank is equal to the weight of the professor. v. If M = 0, the professor and the plank are always in static equilibrium, as long as L>t. Answer: ( Submit All Answers Not yet correct, tries 5/15

NOTE: the answer is NOT FTFTF, FTTTT, FTFTT, FTTTF

Answer 1

FTFFT

FBD Professor FBD Professor FBD Plank ang -42- FN mpg Fu = mg-T -0 or T = mg-FN EF = R+ T-mpg-Mg - FN=0 = R +T-mpg -Mg-mg+T=0 = 27+R -(mp+M+ m)g=0 ---® moment about hinge EM = LT-LMg - e Fs - Ļ mpg = 0