Answer:
Ethan's tangential speed is twice as Rebecca's.
Explanation:
Let [tex]r[/tex] be the distance from the center of the platform to Rebecca's horse, [tex]v_R[/tex] Rebecca's tangential speed, [tex]v_E[/tex] the Ethan's tangential speed and [tex]\omega[/tex] the merry-go-round angular speed. The distance from the center of the platform to Ethan's horse is [tex]2r[/tex]. The angular speed is related to the tangential speed by the equation:
[tex]\omega =\frac{v}{R}[/tex]
Since the angular speed is the same for Ethan and Rebecca, we have that:
[tex]\frac{v_E}{2r}=\frac{v_R}{r}[/tex]
Now, solving for [tex]v_E[/tex] we get:
[tex]v_E=2v_R[/tex]
It means that Ethan's tangential speed is twice as Rebecca's.