Question

How do you identify the larger force? What rule do you use to identify which is the larger force to use the Belt friction equation? Could you explain why rotate counterclockwise, D is the larger force and rotate clockwise, B is the larger force?

7:17 PM Sun Jul 19 40% < + : 0 24 in. r=8 in. E 8.115 The speed of the brake drum shown is controlled by a belt attached to the control bar AD. A force P with a magnitude of 25 lb is applied to the control bar at A. Determine the magnitude of the couple being applied to the drum knowing that the coefficient of kinetic friction between the belt and the drum is 0.25, that a = 4 in., and that the drum is rotating at a constant speed (a) counterclockwise, (b) clockwise. B GZ Me=0 0(4in)-(B)Lizin) + (2510 (28)=0 40 = 12B-700 40=1262-190)-700 M=168-8)(2)-(31.4)(H) = 299. -22-320 = -700 D=31.416 $=06.2010) TO B= 2.190

Answer 1

soin cotton example of Belt Drive lets take an Tight side (T) اوراما А B. Driven ured Driving slack side (T2) Belt rotates TI the T pulley. pulley T qutates but o Tz 72 >> since Driving pulley Driven pully Driving pulley is pulling the Bet at A hence it should be tight side hence it should be while pushing at B slack fide For Dolven pulley , Belt is rotating tight hence (Ti>2) the pulley T>T pe Ti is Te is slack.

Now in given question pulley we driviry and pulley usly belt to stop stop it (Brake) hena pulling side must be tight il side while side at which belt is leaving must be slack side Trick to Remember ID Brake questions always focus on Arrow notation. of side the at which praw arrow is pointly will be be tight side. T T TITL S Ta Tight 'T Ta side Ti
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