Apiston having 7.23 g of steam at 110°c increases its temperature by 35°c. at the same time it expands from a volume of 2.00 l to 8.00 l against a constant external pressure of 0.985 bar. the heat capacity of stearm is 1.996 j g-1 kl. calculate q, w. δυ, and δη in joules. w-

Answer : The value of is 505 J, -599 J, -94 J and -693 J respectively.

Explanation : Given,

Mass of steam = 7.23 g

Initial temperature =

Final temperature =

Initial volume = 2 L

Final volume = 8 L

External pressure = 0.985 bar

Heat capacity of steam = 1.996 J/g.K

First law of thermodynamic : It states that the energy can not be created or destroyed, it can only change or transfer from one state to another state.

As per first law of thermodynamic,

First we have to calculate the heat absorbed by the system.

Formula used :

or,

where,

Q = heat absorbed by the system = ?

m = mass of steam = 7.23 g

= heat capacity of steam =

= initial temperature  =

= final temperature  =

Now put all the given value in the above formula, we get:

Now we have to calculate the work done.

Formula used :

where,

w = work done  = ?

= external pressure = 0.985 bar = 0.985 atm   (1 bar = 1 atm)

= initial volume of gas = 2.00 L

= final volume of gas = 8.00 L

Now put all the given values in the above formula, we get :

conversion used : (1 L.atm = 101.3 J)

Now we have to calculate the change in internal energy of the system.

Now we have to calculate the change in enthalpy of the system.

Formula used :

Therefore, the value of is 505 J, -599 J, -94 J and -693 J respectively.

a solenoid is created by wrapping a l = 90 m long wire around a hollow tube of diameter d = 4.5 cm.   the wire diameter is d = 0.9 mm.   the solenoid wire is then connected to a power supply so that a current of i = 9 a flows through the wire.

randomized variablesl = 90 m

d = 4.5 cm

d = 0.9 mm

i = 9 a                                          

write an expression for the number of turns, n, in the solenoid. you do not need to take into account the diameter of the wire in this calculation.

calculate the number of turns, n, in the solenoid.

write an expression for the length of the solenoid (l2) in terms of the diameter of the hollow tube d.

calculate the length of the solenoid (l2)   in meters.

calculate the magnitude of the magnetic field at the center of the solenoid in teslas.

explanation:

acceleration = (change in speed) / (time for the change)

change in speed = (20-120)= -100 m/s.

1.5 min = 90 sec

acceleration = -100/90 = -1.11 m/s^2.

we don't care about the 150kg or the 2,500 meters. they don't make any difference.

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