Step-by-step explanation:
Given that,
The length of a wire, L = 48 m
Current in the wire, I = 18 A (west to east)
The magnetic field in the wire, B =
(towards south)
The magnetic force acting on the wire is given by :

Using right hand rule, the direction of magnetic force is upwards.
The answer is: [A]:
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"According to the rules, how many swimmers are on a team?"
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Answer:
The expression equivalent is 12 (2x+1)
Step-by-step explanation:
Answer:
C = 13
Step-by-step explanation:
A²+B²=C²
where c is the hypothenuse
5²+12²=c²
25+144=c²
169=c²
√169 = c
13 = c
Answer:
The solution of this system is x=9/4, y=5/2, and z=-13/8
Step-by-step explanation:
<em>1. Writing the equations in matrix form</em>
The system of linear equations given can be written in matrix form as
![\left[\begin{array}{ccc}1&0&2\\2&-1&0\\0&3&4\end{array}\right]\left[\begin{array}{c}x&y&z\end{array}\right] = \left[\begin{array}{c}-1&2&1\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%260%262%5C%5C2%26-1%260%5C%5C0%263%264%5Cend%7Barray%7D%5Cright%5D%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7Dx%26y%26z%5Cend%7Barray%7D%5Cright%5D%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D-1%262%261%5Cend%7Barray%7D%5Cright%5D)
Writing
A = ![\left[\begin{array}{ccc}1&0&2\\2&-1&0\\0&3&4\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%260%262%5C%5C2%26-1%260%5C%5C0%263%264%5Cend%7Barray%7D%5Cright%5D)
X = ![\left[\begin{array}{c}x&y&z\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7Dx%26y%26z%5Cend%7Barray%7D%5Cright%5D)
B = ![\left[\begin{array}{c}-1&2&1\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D-1%262%261%5Cend%7Barray%7D%5Cright%5D)
we have
AX=B
This is the matrix form of the simultaneous equations.
<em>2. Solving the simultaneous equations</em>
<em>Given</em>
AX=B
we can multiply both sides by the inverse of A

We know that
, the identity matrix, so

All we need to do is calculate the inverse of the matrix of coefficients, and finally perform matrix multiplication.
<em>3. Calculate the inverse of the matrix of coefficients</em>
A = ![\left[\begin{array}{ccc}1&0&2\\2&-1&0\\0&3&4\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%260%262%5C%5C2%26-1%260%5C%5C0%263%264%5Cend%7Barray%7D%5Cright%5D)
To find the inverse matrix, augment it with the identity matrix and perform row operations trying to make the identity matrix to the left. Then to the right will be inverse matrix.
![\left[\begin{array}{ccc|ccc}1&0&2&1&0&0\\2&-1&0&0&1&0\\0&3&4&0&0&1\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cccc%7D1%260%262%261%260%260%5C%5C2%26-1%260%260%261%260%5C%5C0%263%264%260%260%261%5Cend%7Barray%7D%5Cright%5D)
- <em>Make zeros in column 1 except the entry at row 1, column 1. Subtract row 1 multiplied by 2 from row 2</em>
![\left[\begin{array}{ccc|ccc}1&0&2&1&0&0\\0&-1&-4&-2&1&0\\0&3&4&0&0&1\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cccc%7D1%260%262%261%260%260%5C%5C0%26-1%26-4%26-2%261%260%5C%5C0%263%264%260%260%261%5Cend%7Barray%7D%5Cright%5D)
- <em>Make zeros in column 2 except the entry at row 2, column 2. Add row 2 multiplied by 3 to row 3</em>
![\left[\begin{array}{ccc|ccc}1&0&2&1&0&0\\0&-1&-4&-2&1&0\\0&0&-8&-6&3&1\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cccc%7D1%260%262%261%260%260%5C%5C0%26-1%26-4%26-2%261%260%5C%5C0%260%26-8%26-6%263%261%5Cend%7Barray%7D%5Cright%5D)
- <em>Multiply row 2 by −1</em>
![\left[\begin{array}{ccc|ccc}1&0&2&1&0&0\\0&1&4&2&-1&0\\0&0&-8&-6&3&1\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cccc%7D1%260%262%261%260%260%5C%5C0%261%264%262%26-1%260%5C%5C0%260%26-8%26-6%263%261%5Cend%7Barray%7D%5Cright%5D)
- <em>Make zeros in column 3 except the entry at row 3, column 3. Divide row 3 by −8</em>
![\left[\begin{array}{ccc|ccc}1&0&2&1&0&0\\0&1&4&2&-1&0\\0&0&1&3/4&-3/8&-1/8\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cccc%7D1%260%262%261%260%260%5C%5C0%261%264%262%26-1%260%5C%5C0%260%261%263%2F4%26-3%2F8%26-1%2F8%5Cend%7Barray%7D%5Cright%5D)
- <em>Subtract row 3 multiplied by 2 from row 1</em>
![\left[\begin{array}{ccc|ccc}1&0&0&-1/2&3/4&1/4\\0&1&4&2&-1&0\\0&0&1&3/4&-3/8&-1/8\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cccc%7D1%260%260%26-1%2F2%263%2F4%261%2F4%5C%5C0%261%264%262%26-1%260%5C%5C0%260%261%263%2F4%26-3%2F8%26-1%2F8%5Cend%7Barray%7D%5Cright%5D)
- <em>Subtract row 3 multiplied by 4 from row 2</em>
![\left[\begin{array}{ccc|ccc}1&0&0&-1/2&3/4&1/4\\0&1&0&-1&1/2&1/2\\0&0&1&3/4&-3/8&-1/8\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cccc%7D1%260%260%26-1%2F2%263%2F4%261%2F4%5C%5C0%261%260%26-1%261%2F2%261%2F2%5C%5C0%260%261%263%2F4%26-3%2F8%26-1%2F8%5Cend%7Barray%7D%5Cright%5D)
As can be seen, we have obtained the identity matrix to the left. So, we are done.
![A^{-1} = \left[\begin{array}{ccc}-1/2&3/4&1/4\\-1&1/2&1/2\\3/4&-3/8&-1/8\end{array}\right]](https://tex.z-dn.net/?f=A%5E%7B-1%7D%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-1%2F2%263%2F4%261%2F4%5C%5C-1%261%2F2%261%2F2%5C%5C3%2F4%26-3%2F8%26-1%2F8%5Cend%7Barray%7D%5Cright%5D)
<em>4. Find the solution
</em>
![X= \left[\begin{array}{ccc}-1/2&3/4&1/4\\-1&1/2&1/2\\3/4&-3/8&-1/8\end{array}\right]\cdot \left[\begin{array}{c}-1&2&1\end{array}\right] = \left[\begin{array}{c}9/4&5/2&-13/8\end{array}\right]](https://tex.z-dn.net/?f=X%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-1%2F2%263%2F4%261%2F4%5C%5C-1%261%2F2%261%2F2%5C%5C3%2F4%26-3%2F8%26-1%2F8%5Cend%7Barray%7D%5Cright%5D%5Ccdot%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D-1%262%261%5Cend%7Barray%7D%5Cright%5D%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D9%2F4%265%2F2%26-13%2F8%5Cend%7Barray%7D%5Cright%5D)