Answer:
0.453 m/s
Explanation:
Assuming the handle has diameter of 0.4 m while inner part diameter is 0.1 m then the circumference of outer part is
where d is diameter and subscript h denote handle. By substituting 0.4 for the handle's diameter then cirxumference of outer part is 
The rate of rotation will then be 1.81/1.256=1.441 rev/s
Similarly, circumference of inner part will be
where subscript i represent inner. Substituting 0.1 for inner diameter then

The rate of rotation found for outer handle applies for inner hence speed will be 0.3142*1.441=0.453 m/s
Answer: I am pretty sure that you should pick radio waves.
Explanation: The scientist should use radio waves. I think this because you can use the radio waves to analyze the signals from outer space. This will work much better than anything there, to analyze it the best possible.
The best I could do.
Answer:
15m/s²
Explanation:
Given parameters:
Initial velocity = 10m/s
Final velocity = 40m/s
Time taken = 2s
Unknown:
Average acceleration = ?
Solution:
Acceleration is the rate of change of velocity with time;
Acceleration =
Acceleration =
= 15m/s²