Answer:
Ethan's tangential speed is twice as Rebecca's.
Step-by-step explanation:
Let
be the distance from the center of the platform to Rebecca's horse,
Rebecca's tangential speed,
the Ethan's tangential speed and
the merry-go-round angular speed. The distance from the center of the platform to Ethan's horse is
. The angular speed is related to the tangential speed by the equation:
![\omega =(v)/(R)](https://img.qammunity.org/2021/formulas/physics/college/svmhu5q97ba3p2je352mzfeuxechqkz5j5.png)
Since the angular speed is the same for Ethan and Rebecca, we have that:
![(v_E)/(2r)=(v_R)/(r)](https://img.qammunity.org/2021/formulas/physics/high-school/jeqgx9xej0reh40pc66gebi36rdstppjzg.png)
Now, solving for
we get:
![v_E=2v_R](https://img.qammunity.org/2021/formulas/physics/high-school/a3ishtjwzfalhxo1j8oomaqx8dvjjz2mfc.png)
It means that Ethan's tangential speed is twice as Rebecca's.