The 50-lb block A and the 25-lb block B are supported by an incline that is held in the position.
Knowing that the coefficient of static friction is 0.15 between the two blocks and zero between block B and the incline, determine the value of θ for which motion is impending.

Explanation:

since motion is impends F= μN between A+B

Free body diagram of block A impending motion  

∑

∑μ(1)

-μ(1)

Free body diagram of block B impending motion

∑

∑μ(1)μ(2)

T=μ(1)(50)μ(2)(75)

From Eq1 and Eq2

0=μ(1)μ(2)

substituting in for μ(1)=0.15 and μ(2)=0 we have

wavelength variability is the right one

trig 15.3 cos