You could use clay, sticks, rocks, Legos,
A flow of electrical charge from one place to another
is called an electric current. It doesn't need to be steady.
(1) The position around equilibrium of an object in simple harmonic motion is described by

where
A is the amplitude of the motion

is the angular frequency.
The velocity is the derivative of the position:

where

is the maximum velocity of the object.
The acceleration is the derivative of the velocity:

where

is the maximum acceleration of the object.
We know from the problem both maximum velocity and maximum acceleration:


From the first equation, we get

(1)
and if we substitute this into the second equation, we find the angular fequency

while the amplitude is (using (1)):

(b) We found in the previous step that the angular frequency of the motion is

But the angular frequency is related to the period by

and so, the period is
An experimental variable is a variable that is being tested to answer a scientific question; while a control variable is a variable that is not being altered or changed during the experiement to serve as a constant. An example of an experimental variable is plant food solution A and whether it makes a kidney bean sprout faster than plant food solution B. An example of a control variable is water, because there is no plant food mixed in to create a solution; so it will serve as a natural constant.