Please help A light, inextensible cord passes over a frictionless pulley as show
ID: 1862306 • Letter: P
Question
Please help
A light, inextensible cord passes over a frictionless pulley as shown in figure below. One end of the rope is attached to a block, and a force P is applied to the other end. Block A weighs 600 lb and block B weighs 1000 lb. The coefficient of friction between the blocks 0.33, and the coefficient of friction between block B and the floor is 0.25. Determine if the system would be in equilibrium for P = 400 lb. Determine the maximum P for which the system is in equilibrium. (Answer: P = 800 lb)Explanation / Answer
Horizontal force due to 500 lb= 300 lb
Vertical force due to 500 lb= 300 lb
Net horizontal force=P-300
For equilibrium,
N=600+1000+400=2000 lb
maximum frictional force=0.25*2000=500 lb
P-300=frictional force
For P=400 lb
frictional force=100 lb < 500 lb
Hence,system is stationary
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For maximum P friction should be maximum
P-300=frictional force
P-300=500
P=800 lb
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