Answer: 27.33 g water
Step-by-step explanation:
For this problem, we will need to use the equation for heat: q=mCΔT. Since we are given heat, change in temperature, and specific heat, all we have to do is plug them in to find grams.
4000J=m(4.181J/g°C)(100-65°C) [find change in temperature]
4000J=m(4.181J/g°C)(35°C) [divide both sides by specific heat and change in temperature]
m=27.33 g
This is a system of equations, and I am assuming that you are being asked to solve it.
This is finding the point where these two lines intersect.
The key to solving these algebraically is finding one part in terms of another part and substituting.
We can solve this system by Gaussian elimination, first by multiplying the second equation in its entirety by 2, so that the x-terms will cancel.
We have

and

.
The last equation is rewritten as

.
Now, we cancel the x-terms.



We have our value for y, so we just plug this back into any of the original equations to get x.

Thus, the solution to the system of equations is the point

.
Answer:
C
Step-by-step explanation:
Due to the fact that you are surveying more people and that those people are differentiated there will be a more representative answer rather than a biased one.
Answer:
2
Step-by-step explanation:
Answer:
7.5
Step-by-step explanation:
It is longer than 5, so cross 2.5 and 5 out, 10 is too big, so 7.5 is the correct answer