You have a distance and a time so you can work out the bikes speed which would be distance/time so 40mph.
I think that the oceanic water particles mainly move in circles greater in the oceans surface because of how big the waves can be and how wind and air impact the motion. The water particles move more on the surface because of the other factors that impact it such as people, wind, air, etc...
<span>The speed of sound needs to be given, in the proper form. This will allow for the proper conversion (namely, a multiplication by the Mach rate) to find the actual speed that the aircraft is traveling, compared to how fast sound travels.</span>