Elastic potential energy.
When you stretch a rubber band it has the "potential" to do work, to fly in a given direction. In doing so it changes it's elastic potential energy to kinetic energy.
To solve this problem we will apply the concepts related to wavelength as the rate of change of the speed of the wave over the frequency. Mathematically this is

Here,
v = Wave velocity
f = Frequency,
Replacing with our values we have that,

\lambda = 0.68m
The distance to move one speaker is half this

Therefore the minimum distance will be 0.34m
Answer: 
Explanation:
We are told both planets describe a circular orbit around the star S. So, let's approach this problem begining with the angular velocity
of the planet P1 with a period
:
(1)
Where:
is the velocity of planet P1
is the radius of the orbit of planet P1
Finding
:
(2)
(3)
(4)
On the other hand, we know the gravitational force
between the star S with mass
and the planet P1 with mass
is:
(5)
Where
is the Gravitational Constant and its value is 
In addition, the centripetal force
exerted on the planet is:
(6)
Assuming this system is in equilibrium:
(7)
Substituting (5) and (6) in (7):
(8)
Finding
:
(9)
(10)
Finally:
(11) This is the mass of the star S
Answer:
The answer is a=b=c=3.833 cm
Explanation:
Lets call the variables a=side a b=side b c=side c
We have that the formula of the equilateral triangle for its height is:
1)h=(1/2)*root(3)*a
2) If we resolve the equation we have
2.1)2h=root(3)*a
2.2)(2h/root(3))=a
3) After the replacement of each value we have that
a=2*3.32/1.73205
a=3.833 cm
And we know that the equilateral triangle has the same value for each side so a=b=c=3.833 cm