<span>It's going to rain this weekend.</span>
Answer:

Explanation:
It is given that,
Radius of the circular loop, r = 0.7 m
Magnetic field, B = 0.44 T
In 0.14 s the wire is reshaped from a circle into a square, but remains in the same plane.
Area of the circular wire,


For the area of square,
The circumference of wire, 
Side of square, 
Area of square, 
An emf is induced in the loop due to change in its area. The induced emf is given by :



So, the magnitude of the average induced emf is 1.10 volts. Hence, this is the required solution.
Answer:
24) W = 75 [J]; 25) W = 1794[J]; 26) n = 8.8 (times) or 9 (times)
Explanation:
24) This problem can be solved by means of the following equation.

where:
DU = internal energy difference [J]
Q = Heat transfer [J]
W = work [J]
Since there are no temperature changes the internal energy change is equal to zero
DU = 0
therefore:

The work is equal to the heat transfered, W = 75 [J].
25) The heat transfer can be calculated by means of the following equation.
![Q = m*c_{p}*DT\\where:\\m = mass = 0.4[kg]\\c_{p} = specific heat = 897[J/kg*K]\\DT= 5 [C]](https://tex.z-dn.net/?f=Q%20%3D%20m%2Ac_%7Bp%7D%2ADT%5C%5Cwhere%3A%5C%5Cm%20%3D%20mass%20%3D%200.4%5Bkg%5D%5C%5Cc_%7Bp%7D%20%3D%20specific%20heat%20%3D%20897%5BJ%2Fkg%2AK%5D%5C%5CDT%3D%205%20%5BC%5D)
Q = 0.4*897*5 = 1794[J]
Work is equal to heat transfer, W = 1794[J]
26) Each time the bag falls the potential energy is transformed into heat energy, which is released into the environment. In this way the potential energy is equal to the developed heat.

where:
m = mass = 0.5[kg]
g = gravity = 9.81[m/s^2]
h = 1.5 [m]
![E_{p}=0.5*9.81*1.5\\E_{p}=7.36[J]](https://tex.z-dn.net/?f=E_%7Bp%7D%3D0.5%2A9.81%2A1.5%5C%5CE_%7Bp%7D%3D7.36%5BJ%5D)
The heat developed can be calculated by means of the following equation.
![Q=m*c_{p}*DT\\Q=0.5*130*1\\Q=65[J]](https://tex.z-dn.net/?f=Q%3Dm%2Ac_%7Bp%7D%2ADT%5C%5CQ%3D0.5%2A130%2A1%5C%5CQ%3D65%5BJ%5D)
The number of times will be calculated as follows
n = 65/7.36
n = 8.8 (times) or 9 (times)
Answer:
F = - 2 A x - B
Explanation:
The force and potential energy are related by the expression
F = - dU / dx i ^ -dU / dy j ^ - dU / dz k ^
Where i ^, j ^, k ^ are the unit vectors on the x and z axis
The potential they give us is
U (x) = A x² + B x + C
Let's calculate the derivatives
dU / dx = A 2x + B + 0
The other derivatives are zero because the potential does not depend on these variables.
Let's calculate the strength
F = - 2 A x - B
Answer:
No, they will not change.
Explanation: