Answer:
The positive displacement from the midpoint of its motion at the speed equal one half of its maximum speed is 3.56 cm.
Explanation:
Maximum speed is :
v (max) = Aω
Speed v at any displacement y is given by
[tex]v^{2}[/tex] = [tex]w^{2}[/tex] ([tex]A^{2}[/tex] - [tex]y^{2}[/tex]) ........................................................ i
And,
v = [tex]\frac{1}{2}[/tex] v (max)
or, 2 × v = Aω .................................................... ii
Eliminating ω from equations i and ii,
[tex]\frac{1}{4}[/tex] [tex]A^{2}[/tex] [tex]w^{2}[/tex] = [tex]w^{2}[/tex] ( [tex]A^{2}[/tex] - [tex]y^{2}[/tex])
or, [tex]y^{2}[/tex] = ([tex]\frac{3}{4}[/tex]) [tex]A^{2}[/tex] =([tex]\frac{3}{4}[/tex]) [tex]2.18^{2}[/tex]
or, y = 3.56 cm.