Answer:
Vy = 80.5 [m/s]
Explanation:
In order to solve this problem we must use the Pythagorean theorem.
V = 90 [m/s]
The components are Vx and Vy:
Therefore:

where:
Vy = 2*Vx ; because one is twice of the other.
![90 = \sqrt{v_{x}^{2} +(2*v_{x})^{2} }\\ 90 =\sqrt{v_{x}^{2}+4*v_{x}^{2}} \\90 =\sqrt{5v_{x}^{2}} \\90=2.23*v_{x} \\v_{x}=40.25[m/s]](https://tex.z-dn.net/?f=90%20%3D%20%5Csqrt%7Bv_%7Bx%7D%5E%7B2%7D%20%20%2B%282%2Av_%7Bx%7D%29%5E%7B2%7D%20%7D%5C%5C%2090%20%3D%5Csqrt%7Bv_%7Bx%7D%5E%7B2%7D%2B4%2Av_%7Bx%7D%5E%7B2%7D%7D%20%5C%5C90%20%3D%5Csqrt%7B5v_%7Bx%7D%5E%7B2%7D%7D%20%5C%5C90%3D2.23%2Av_%7Bx%7D%20%5C%5Cv_%7Bx%7D%3D40.25%5Bm%2Fs%5D)
and the bigger vector is:
Vy = 40.25*2
Vy = 80.5 [m/s]
In order to build a hypothesis, Joan should take an educated guess at what the effect of adding salt to the water will be on the water's boiling point. For example, the hypothesis may be,"The boiling point will increase". This hypothesis is one that can be verified or rejected via experimentation. The next step for Joan would be to set up an experiment to test this hypothesis.
I can confirm, your answer is 800J (Or 800 Joules)!
I just took the test and this was the correct answer :)