To find the angular displacement, we have to transform 157.5 revolutions to radians. We know that 1 revolution equals 2pi radians
[tex]1\text{rev}=2\pi[/tex]Let's use the following proportion to find the angular displacement for 157.5 revolutions.
[tex]\frac{1\text{rev}}{157.5\text{rev}}=\frac{2\pi}{x}[/tex]Then, we solve for x
[tex]\begin{gathered} x=\frac{2\pi\cdot157.5}{1} \\ x=315\pi \end{gathered}[/tex]But, pi = 3.14, so
[tex]\begin{gathered} x=315\cdot3.14\text{rad} \\ x=989.1rad \end{gathered}[/tex]