Given: A force of 100 lb, with variable direction THETA, acts on an 85 lb block.
Find: If the acceleration of the block is maximum when THETA= 11.31 degrees, determine the numerical value of the maximum acceleration when the coefficient of friction is 0.20.
Any help is appreciated! Thanks so much!
Find: If the acceleration of the block is maximum when THETA= 11.31 degrees, determine the numerical value of the maximum acceleration when the coefficient of friction is 0.20.
Any help is appreciated! Thanks so much!
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(This would be easier if I could draw a picture).
Do a free body diagram of the block and you would find that the net horizontal force is F*cos(theta)-(coefficient of friction)*(Normal Force).
The normal force is the net vertical force which will = (Weight)-F*sin(theta)
Plugging in the numbers you provided,
normal force = 85-100*sin(11.31) = 65.39 lb.
Net horizontal force = 100*cos(11.31)-(.2)*(65.39) = 84.98 lb.
Using newton's second law, the acceleration of the block would then be (84.98 lbf)/(85 lbm) = 32.2 ft/(s^2). Note that the English units are a pain here and you need conversion factors to do newton's second law.
Do a free body diagram of the block and you would find that the net horizontal force is F*cos(theta)-(coefficient of friction)*(Normal Force).
The normal force is the net vertical force which will = (Weight)-F*sin(theta)
Plugging in the numbers you provided,
normal force = 85-100*sin(11.31) = 65.39 lb.
Net horizontal force = 100*cos(11.31)-(.2)*(65.39) = 84.98 lb.
Using newton's second law, the acceleration of the block would then be (84.98 lbf)/(85 lbm) = 32.2 ft/(s^2). Note that the English units are a pain here and you need conversion factors to do newton's second law.