2.-When water boils at 2 atm, the heat of vaporization is 2.2 106 J/kg, and the boiling point is 120ºC. At that pressure, 1 kg of steam occupies a volume of 0.824 m3, while 1 kg of water occupies 10-3 m3. a) Find the work done when 1 kg of steam is formed at that temperature.
b) Calculate the increase in internal energy.

a) Find the work done when 1 kg of steam is formed at that temperature.

b) Calculate the increase in internal energy.

Cost of 7 gallons=$24.50

Cost of 1 gallon=24.50/7=3.5

Cost of 15 gallons=15*3.5=52.5

Cost of 15 gallons will be $52.5

The answer is in the image 

The answer is in the image 

The solution is in the following image

The answer is in the image 

The solution is given in the image below

Speed=Distance/time

Here,

distance=15m

time=1sec

speed=15/1=15m/sec

Distance=Speed*time

time=15min=15*60sec=900sec

Distance travelled in 15 min=15*900=13,500m

=13500/1000 km=13.5Km

The wood before starting =12 feet

Left wood=6 feet

Wood used till now=12-6=6 feet

Picture frame built till now= 6/(3/4)

=8 pieces

Therefore, till now 8 pieces have been made.

Salesperson will make 6% of 1800

=(6/100)*1800

=108

Salesperson will make $108 in $1800 sales