Answer
Upper: $\approx166 N$ and lower: $\approx114 N$
Work Step by Step
$255= Ucos 20^\circ+L cos 30^\circ$ ... (1)
$0= Usin 20^\circ-L sin 30^\circ$
Here, U = upper level and L =lower level
$U=\frac{L sin 30^\circ}{ sin 20^\circ}$
Equation (1), becomes
$255= \frac{L sin 30^\circ}{ sin 20^\circ}cos 20^\circ+L cos 30^\circ$
$L=\frac{255}{\dfrac{sin 30^\circ}{ sin 20^\circ}cos 20^\circ
+cos 30^\circ}\approx 113.851 N$
$U=\dfrac{(113.851 N sin 30^\circ}{ sin 20^\circ}\approx 166.439 N$
Hence, Upper: $\approx166 N$ and lower: $\approx114 N$
