1) Let's call
![V_S](https://tex.z-dn.net/?f=V_S)
the speed of the southbound boat, and
![V_E=V_s+3~mph](https://tex.z-dn.net/?f=V_E%3DV_s%2B3~mph)
the speed of the eastbound boat, which is 3 mph faster than the southbound boat. We can write the law of motion for the two boats:
![S_E(t)=V_E t=(V_S+3)t](https://tex.z-dn.net/?f=%20S_E%28t%29%3DV_E%20t%3D%28V_S%2B3%29t)
![S_S(t)=V_S t](https://tex.z-dn.net/?f=S_S%28t%29%3DV_S%20t)
2) After a time
![t=3~h](https://tex.z-dn.net/?f=t%3D3~h)
, the two boats are
![45~mi](https://tex.z-dn.net/?f=45~mi)
apart. Using the laws of motion written at step 1, we can write the distance the two boats covered:
![S_E(3~h)=3(V_S+3)=3V_S+9](https://tex.z-dn.net/?f=S_E%283~h%29%3D3%28V_S%2B3%29%3D3V_S%2B9)
![S_S(3~h)=3V_S](https://tex.z-dn.net/?f=S_S%283~h%29%3D3V_S)
The two boats travelled in perpendicular directions. Therefore, we can imagine the distance between them (45 mi) being the hypotenuse of a triangle, of which
![S_E](https://tex.z-dn.net/?f=S_E)
and
![S_S](https://tex.z-dn.net/?f=S_S)
are the two sides. Therefore, we can use Pythagorean theorem and write:
![45= \sqrt{(3V_S)^2+(3V_S+9)^2}](https://tex.z-dn.net/?f=45%3D%20%5Csqrt%7B%283V_S%29%5E2%2B%283V_S%2B9%29%5E2%7D%20%20%20)
Solving this, we find two solutions. Discarding the negative solution, we have
![V_S=9~mph](https://tex.z-dn.net/?f=V_S%3D9~mph)
, which is the speed of the southbound boat.
<span>when air cools , the temperatures drops, the molecules move slowly taking up less space , the amount of space the air takes ups shrinks , or reduce the air pressure
</span>
The magnitude of the acceleration is equal to 31.5 ![m/s^2](https://tex.z-dn.net/?f=m%2Fs%5E2)
<u>Given the following data:</u>
To determine the magnitude of the acceleration:
In Science, the acceleration of a particle in a <u>circle</u> or circular track is known as centripetal acceleration.
<h3>How to calculate
centripetal acceleration.</h3>
Mathematically, centripetal acceleration is given by this formula:
![a = \frac{V^2}{r}](https://tex.z-dn.net/?f=a%20%3D%20%5Cfrac%7BV%5E2%7D%7Br%7D)
Substituting the given parameters into the formula, we have;
![a = \frac{21^2}{14}\\\\a=\frac{441}{14}](https://tex.z-dn.net/?f=a%20%3D%20%5Cfrac%7B21%5E2%7D%7B14%7D%5C%5C%5C%5Ca%3D%5Cfrac%7B441%7D%7B14%7D)
Centripetal acceleration = 31.5 ![m/s^2](https://tex.z-dn.net/?f=m%2Fs%5E2)
Read more on centripetal acceleration here: brainly.com/question/25780931
B. The kinetic energy will decrease.
The answer is D) Cyclones. I am 100% sure on this one, so yeah. Hope this helps, and good luck. :D