Answer:
So coefficient of kinetic friction will be equal to 0.4081
Explanation:
We have given mass of the block m = 0.5 kg
The spring is compressed by length x = 0.2 m
Spring constant of the sprig k = 100 N/m
Blocks moves a horizontal distance of s = 1 m
Work done in stretching the spring is equal to 
This energy will be equal to kinetic energy of the block
And this kinetic energy must be equal to work done by the frictional force
So 


So coefficient of kinetic friction will be equal to 0.4081
I'm a little confused by your question.
If you mean what is popular sovereignty, it is the belief that the governments is made and sustained by the consent of the people that it governs.
Answer:
In both cases, energy will move from an area of higher temperature to an area of lower temperature. So, the energy from room-temperature air will move into the cold water, which warms the water.
Explanation:
The total mechanical energy of the block-spring system is given by the sum of the potential energy and the kinetic energy of the block:

where
k is the spring constant
x is the elongation/compression of the spring
m is the mass of the block
v is the speed of the block
At the point of maximum displacement of the spring, the velocity of the block is zero: v=0, so the kinetic energy is zero and the mechanical energy is just potential energy of the spring:

(1)
where we used x=A, the amplitude (which is the maximum displacement of the spring).
Since we know
A = 11.0 cm= 0.11 m
E = 1.10 J
We can re-arrange (1) to find the spring constant:
Answer:
![B_T=2.0*10^-5[-\hat{i}+\hat{j}]T](https://tex.z-dn.net/?f=B_T%3D2.0%2A10%5E-5%5B-%5Chat%7Bi%7D%2B%5Chat%7Bj%7D%5DT)
Explanation:
To find the magnitude of the magnetic field, you use the following formula for the calculation of the magnetic field generated by a current in a wire:

μo: magnetic permeability of vacuum = 4π*10^-7 T/A
I: current = 6.0 A
r: distance to the wire in which magnetic field is measured
In this case, you have four wires at corners of a square of length 9.0cm = 0.09m
You calculate the magnetic field in one corner. Then, you have to sum the contribution of all magnetic field generated by the other three wires, in the other corners. Furthermore, you have to take into account the direction of such magnetic fields. The direction of the magnetic field is given by the right-hand side rule.
If you assume that the magnetic field is measured in the up-right corner of the square, the wire to the left generates a magnetic field (in the corner in which you measure B) with direction upward (+ j), the wire down (down-right) generates a magnetic field with direction to the left (- i) and the third wire generates a magnetic field with a direction that is 45° over the horizontal in the left direction (you can notice that in the image attached below). The total magnetic field will be:
![B_T=B_1+B_2+B_3\\\\B_{T}=\frac{\mu_o I_1}{2\pi r_1}\hat{j}-\frac{\mu_o I_2}{2\pi r_2}\hat{i}+\frac{\mu_o I_3}{2\pi r_3}[-cos45\hat{i}+sin45\hat{j}]](https://tex.z-dn.net/?f=B_T%3DB_1%2BB_2%2BB_3%5C%5C%5C%5CB_%7BT%7D%3D%5Cfrac%7B%5Cmu_o%20I_1%7D%7B2%5Cpi%20r_1%7D%5Chat%7Bj%7D-%5Cfrac%7B%5Cmu_o%20I_2%7D%7B2%5Cpi%20r_2%7D%5Chat%7Bi%7D%2B%5Cfrac%7B%5Cmu_o%20I_3%7D%7B2%5Cpi%20r_3%7D%5B-cos45%5Chat%7Bi%7D%2Bsin45%5Chat%7Bj%7D%5D)
I1 = I2 = I3 = 6.0A
r1 = 0.09m
r2 = 0.09m

Then you have:
![B_T=\frac{\mu_o I}{2\pi}[(-\frac{1}{r_2}-\frac{cos45}{r_3})\hat{i}+(\frac{1}{r_1}+\frac{sin45}{r_3})\hat{j}}]\\\\B_T=\frac{(4\pi*10^{-7}T/A)(6.0A)}{2\pi}[(-\frac{1}{0.09m}-\frac{cos45}{0.127m})\hat{i}+(\frac{1}{0.09m}+\frac{sin45}{0.127m})]\\\\B_T=\frac{(4\pi*10^{-7}T/A)(6.0A)}{2\pi}[-16.67\hat{i}+16.67\hat{j}]\\\\B_T=2.0*10^-5[-\hat{i}+\hat{j}]T](https://tex.z-dn.net/?f=B_T%3D%5Cfrac%7B%5Cmu_o%20I%7D%7B2%5Cpi%7D%5B%28-%5Cfrac%7B1%7D%7Br_2%7D-%5Cfrac%7Bcos45%7D%7Br_3%7D%29%5Chat%7Bi%7D%2B%28%5Cfrac%7B1%7D%7Br_1%7D%2B%5Cfrac%7Bsin45%7D%7Br_3%7D%29%5Chat%7Bj%7D%7D%5D%5C%5C%5C%5CB_T%3D%5Cfrac%7B%284%5Cpi%2A10%5E%7B-7%7DT%2FA%29%286.0A%29%7D%7B2%5Cpi%7D%5B%28-%5Cfrac%7B1%7D%7B0.09m%7D-%5Cfrac%7Bcos45%7D%7B0.127m%7D%29%5Chat%7Bi%7D%2B%28%5Cfrac%7B1%7D%7B0.09m%7D%2B%5Cfrac%7Bsin45%7D%7B0.127m%7D%29%5D%5C%5C%5C%5CB_T%3D%5Cfrac%7B%284%5Cpi%2A10%5E%7B-7%7DT%2FA%29%286.0A%29%7D%7B2%5Cpi%7D%5B-16.67%5Chat%7Bi%7D%2B16.67%5Chat%7Bj%7D%5D%5C%5C%5C%5CB_T%3D2.0%2A10%5E-5%5B-%5Chat%7Bi%7D%2B%5Chat%7Bj%7D%5DT)