It's most likely the combination of a bucket and the wheel.
Answer:
<em>The difference in pressure between the external air pressure, and the internal air pressure of the middle ear.</em>
Explanation:
First of all, we should note that pressure decreases with height and increases with depth. The air within the middle ear (between the ear drum and the Eustachian tube) adjusts itself to respond to the atmospheric pressure, or when we yawn. At a high altitude like on the hill, the air pressure in the middle ear, is fairly low (this is to balance the low air pressure at this height). While riding down the hill quickly, there is little time for the air pressure in the ear to readjust itself to the increasing external air pressure, causing the external air to push into the ear drum. Along the way, the air within the middle ear is adjusted by the opening of the Eustachian tube, allowing more air into the space in the middle ear to balance the external air pressure. This readjustment causes the ear to pop.
To solve this problem, the concepts related to the balance of forces must be applied. In this case the two forces that must be in balance are the Weight and the centripetal force. Both forces are derived from Newton's second law, one of the linear movement and the other of the angular movement. The centripetal force is given by the function

Here,
m = mass
v =Velocity
R = Radius
And the force product of the weight is given under the function

Here,
m = Mass
g = Gravity
As both forces are in balance we will have





Speed would be


Replacing


The radius must be 12.6m
Explanation:
The forces acting on a massless object (spring, hook, string or wire, if considered massless) will always balance. Balanced forces acting on an object cause it to compress or stretch. The forces acting on a mass will never cancel.
you clap your hands you convert kinetic energy into a potential energy