The answer you are looking for is A
Answer:
each resistor is 540 Ω
Explanation:
Let's assign the letter R to the resistance of the three resistors involved in this problem. So, to start with, the three resistors are placed in parallel, which results in an equivalent resistance
defined by the formula:
![\frac{1}{R_e}=\frac{1}{R} } +\frac{1}{R} } +\frac{1}{R} \\\frac{1}{R_e}=\frac{3}{R} \\R_e=\frac{R}{3}](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7BR_e%7D%3D%5Cfrac%7B1%7D%7BR%7D%20%7D%20%2B%5Cfrac%7B1%7D%7BR%7D%20%7D%20%2B%5Cfrac%7B1%7D%7BR%7D%20%5C%5C%5Cfrac%7B1%7D%7BR_e%7D%3D%5Cfrac%7B3%7D%7BR%7D%20%5C%5CR_e%3D%5Cfrac%7BR%7D%7B3%7D)
Therefore, R/3 is the equivalent resistance of the initial circuit.
In the second circuit, two of the resistors are in parallel, so they are equivalent to:
![\frac{1}{R'_e}=\frac{1}{R} +\frac{1}{R}\\\frac{1}{R'_e}=\frac{2}{R} \\R'_e=\frac{R}{2} \\](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7BR%27_e%7D%3D%5Cfrac%7B1%7D%7BR%7D%20%2B%5Cfrac%7B1%7D%7BR%7D%5C%5C%5Cfrac%7B1%7D%7BR%27_e%7D%3D%5Cfrac%7B2%7D%7BR%7D%20%5C%5CR%27_e%3D%5Cfrac%7BR%7D%7B2%7D%20%5C%5C)
and when this is combined with the third resistor in series, the equivalent resistance (
) of this new circuit becomes the addition of the above calculated resistance plus the resistor R (because these are connected in series):
![R''_e=R'_e+R\\R''_e=\frac{R}{2} +R\\R''_e=\frac{3R}{2}](https://tex.z-dn.net/?f=R%27%27_e%3DR%27_e%2BR%5C%5CR%27%27_e%3D%5Cfrac%7BR%7D%7B2%7D%20%2BR%5C%5CR%27%27_e%3D%5Cfrac%7B3R%7D%7B2%7D)
The problem states that the difference between the equivalent resistances in both circuits is given by:
![R''_e=R_e+630 \,\Omega](https://tex.z-dn.net/?f=R%27%27_e%3DR_e%2B630%20%5C%2C%5COmega)
so, we can replace our found values for the equivalent resistors (which are both in terms of R) and solve for R in this last equation:
![\frac{3R}{2} =\frac{R}{3} +630\,\Omega\\\frac{3R}{2} -\frac{R}{3} = 630\,\Omega\\\frac{7R}{6} = 630\,\Omega\\\\R=\frac{6}{7} *630\,\Omega\\R=540\,\Omega](https://tex.z-dn.net/?f=%5Cfrac%7B3R%7D%7B2%7D%20%3D%5Cfrac%7BR%7D%7B3%7D%20%2B630%5C%2C%5COmega%5C%5C%5Cfrac%7B3R%7D%7B2%7D%20-%5Cfrac%7BR%7D%7B3%7D%20%3D%20630%5C%2C%5COmega%5C%5C%5Cfrac%7B7R%7D%7B6%7D%20%3D%20630%5C%2C%5COmega%5C%5C%5C%5CR%3D%5Cfrac%7B6%7D%7B7%7D%20%2A630%5C%2C%5COmega%5C%5CR%3D540%5C%2C%5COmega)
Answer:
low risk for tissue damage
uses radio waves
the last three are not correct
:)
Answer:
stryo: 1
wood: 1
ice: 1
brick: 2
aluminum: 2.7
Explanation:
d= mass/ total volume
(fyi: for aluminum, they did the subtraction wrong to find the total volume. it is actually 5 or 5.00)
Benthos
Option b is the answer