Colored sparks and rusting.
I think frequency it sounds like the correct answer but I am not completely sure if I am correct
Answer:
v=32.9m/s
Explanation:
The acceleration needed to mantain a circular motion of radius r and speed v is given by the equation 
This is the centripetal acceleration. The person will feel what is called a centrifugal acceleration, of the same value, because he is not in an inertial frame (thus subject to fictitious forces, product of inertia).
We want to know the speed of his head when it is subject to 12.5 times the value of the acceleration of gravity while moving on a 8.84m radius circle, so we must do:

To solve this problem we will derive the expression of the precession period from the moment of inertia of the given object. We will convert the units that are not in SI, and finally we will find the precession period with the variables found. Let's start defining the moment of inertia.

Here,
M = Mass
R = Radius of the hoop
The precession frequency is given as

Here,
M = Mass
g= Acceleration due to gravity
d = Distance of center of mass from pivot
I = Moment of inertia
= Angular velocity
Replacing the value for moment of inertia


The value for our angular velocity is not in SI, then


Replacing our values we have that


The precession frequency is




Therefore the precession period is 5.4s
Answer:

Explanation:
given data:
density of water \rho = 1 gm/cm^3 = 1000 kg/m^3
height of water = 20 cm =0.2 m
Pressure p = 1.01300*10^5 Pa
pressure at bottom



= 1.01300*10^5 - 1000*0.2*9.8
= 99340 Pa
h_[fluid} = 0.307m

