The wavelength of the third resonance of the closed organ pipe is equal to the ratio between the speed of sound and the frequency of the 3rd harmonic:

The relationship between length of a closed pipe and wavelength of the standing waves inside is:

where n is the number of the harmonic. In this case, n=3, so the length of the pipe is

Explanation:
It is given that,
= -40 mi/h,
= -40 mi/h
The negative sign indicates that x and y are decreasing.
We have to find
. Equation for the given variables according to the Pythagoras theorem is as follows.

Now, we will differentiate each side w.r.t 't' as follows.

or, 
So, when x = 4 mi, and y = 3 mi then z = 5 mi.
As, 
= 
= 
= 52
Thus, we can conclude that the cars are approaching at a rate of 52 mi/h.
Answer:
The student is getting different info bc the students probable keeping track of the distance instead of the displacement.
Explanation:
Acceleration is the
rate of change of velocity, a body moving with uniform velocity does not
possess acceleration at all i.e. acceleration is zero
Density is given by:
D = M/V
D = density, M = mass, V = volume
Given values:
M = 3.7g, V = 4.6cm³
Plug in and solve for D:
D = 3.7/4.6
D = 0.80g/cm³