Given Information:
Resistance = R = 14 Ω
Inductance = L = 2.3 H
voltage = V = 100 V
time = t = 0.13 s
Required Information:
(a) energy is being stored in the magnetic field
(b) thermal energy is appearing in the resistance
(c) energy is being delivered by the battery?
Answer:
(a) energy is being stored in the magnetic field ≈ 219 watts
(b) thermal energy is appearing in the resistance ≈ 267 watts
(c) energy is being delivered by the battery ≈ 481 watts
Explanation:
The energy stored in the inductor is given by
The rate at which the energy is being stored in the inductor is given by
The current through the RL circuit is given by
Where τ is the the time constant and is given by
Therefore, eq. 1 becomes
At t = 0.13 seconds
(b) thermal energy is appearing in the resistance
The thermal energy is given by
(c) energy is being delivered by the battery?
The energy delivered by battery is
Answer:
The mass rate of the cooling water required is: 
Explanation:
First, write the energy balance for the condensator: The energy that enters to the equipment is the same that goes out from it; consider that there is no heat transfer to the surroundings and kinetic and potential energy changes are despreciable.
Where w refers to the cooling water and s to the steam flow. Reorganizing,
Write the difference of enthalpy for water as Cp (Tout-Tin):
This equation will let us to calculate the mass rate required. Now, let's get the enthalpy and Cp data. The enthalpies can be read from the steam tables (I attach the tables I used). According to that, 
and 
can be calculated as:
.
The Cp of water at 25ºC (which is the expected average temperature for water) is: 4.176 
. If the average temperature is actually different, it won't mean a considerable mistake. Also we know that 
, so let's work with the limit case, which is 
to calculate the minimum cooling water mass rate required (A higher one will give a lower temperature difference as a result). Finally, replace data:
When speed is combined with strength it is power
It is the energy an object has because of its motion.
