To solve the problem it is necessary to apply the concepts related to Force of Friction and Tension between the two bodies.
In this way,
The total mass of the cars would be,


Therefore the friction force at 29Km / h would be,




In this way the tension exerts between first car and locomotive is,



Therefore the tension in the coupling between the car and the locomotive is 
The correct matches are as follows:
<span>Troposphere
A) Layer closest to the Earth where all weather occurs
Mesosphere
</span>C) temperature remains constant as elevation increases<span>
Mesopause
</span>D) temperature remains at a constant zero degrees Celsius as elevation increases<span>
Stratosphere
</span>E) begins between 50-60km and decreases in temperature as elevation increases <span>
Stratopause
</span> B) temperature increases as elevation increases
Hope this answers the question. Have a nice day.
Answer:
Explanation:
In order to answer this problem you have to know the depth of the column, we say R, this information is important because allows you to compute some harmonic of the tube. With this information you can compute the depth of the colum of air, by taking tino account that the new depth is R-L.
To find the fundamental mode you use:

n: mode of the sound
vs: sound speed
L: length of the column of air in the tube.
A) The fundamental mode id obtained for n=1:

B) For the 3rd harmonic you have:

C) For the 2nd harmonic:

Pb, if compared to Ca it is less reactive and it is a transition metal, and is highly stable alone.