Please help,thanks in advance Figure 3 shows blocks A & B connected by flexible,

Question

Please help,thanks in advance

Figure 3 shows blocks A & B connected by flexible, inextensible cords passing over fnctonless pulleys The coefficients of friction of block A are i+" 0 30 and A-020 while at B they are .-040) and .-030. a) Determine the tension in the cords attached to the blocks A & B if friction is zero b) c) For case (b) find the magnitude and direction of the friction acting on each d) Under what conditions the system is stationary Determine the tension in the cords attached to the blocks A & B considering friction block e) Show free body diagram for each case 300Kg Figure 3

Explanation / Answer

a)let tension in chord be T

from free body diagram of block A,we get

300*9.8*(3/5) -T =300a...(i)

From free body diagram of block B,we get

2T-200*9.8*(4/5) = 200a....(ii)

Solving (i) and (ii) we get

T=1029 N

b)since the blocks will be moving,kinetic friction force will be mobilied

Considering free body diagram of block A

300*9.8*(3/5) -T-(0.2*300*9.8*4/5)=300a....(i)1293.6

Considering free body diagram of block B

2T-200*9.8*4/5-(0.3*200*9.8*3/5) =200a....(ii)1920.8

Solving (i) and (ii) we get

T=1043.7

c)friction force on block A=0.2*300*9.8*4/5=470.4 N(upwards along the incline)

Friction force on block B=0.3*200*9.8*3/5=352.8 N(acting downwards along the incline)

d)the blocks will be stationary if for the given values of static friction values, the inclination of the inclines are adjusted such the net force acting on the blocks is zero and static friction is mobilised

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