3.60 A = 3.60 coulombs of charge per second
(3.60 Coul/sec) x (15.3 sec) = 55.08 coulombs of charge
1 coulomb of charge is carried by 6.25 x 10^18 electrons
Number of electrons =
(55.08 Coul) x (6.25 x 10^18 e/coul) = <em>3.4425 x 10^20 electrons</em>
Answer:
7.46 J/kg/K
Explanation:
The heat absorbed or lost is:
q = mCΔT
where m is the mass, C is the heat capacity, and ΔT is the change in temperature.
Given q = 15.0 J, m = 0.201 kg, and ΔT = 10.0 °C:
15.0 J = (0.201 kg) C (10.0 °C)
C = 7.46 J/kg/°C
Which is the same as 7.46 J/kg/K.
The electron is accelerated through a potential difference of

, so the kinetic energy gained by the electron is equal to its variation of electrical potential energy:

where
m is the electron mass
v is the final speed of the electron
e is the electron charge

is the potential difference
Re-arranging this equation, we can find the speed of the electron before entering the magnetic field:

Now the electron enters the magnetic field. The Lorentz force provides the centripetal force that keeps the electron in circular orbit:

where B is the intensity of the magnetic field and r is the orbital radius. Since the radius is r=25 cm=0.25 m, we can re-arrange this equation to find B:
Answer:
The amount of work must be do to rotate the bar magnet is 151.2 J
Explanation:
Given:
Magnetic moment

Magnetic field
T
To find work do to rotate the bar magnet,
From the formula of work done in case of magnetic field,

Here
changes 0 to 180
But 


J
Therefore, the amount of work must be do to rotate the bar magnet is 151.2 J