Problem $2(10$ points$)-$ Energy Balance with Ideal Gas

A rigid closed box with a paddle wheel contains air as shown in

the image on the right. The air is initially at a temperature of $27$

Celsius and a pressure of $1\mathrm{.}4$ atm $.$ The volume of the box is $60$

liters. The paddle wheel is then turned on and stirs the gas until

the gas reaches $150$ Celsius. During this process, $2$ kJ of heat is

transferred from inside of the box to the surrounding

environment and the change in specific internal energy of the air

is $u=u_2-u_1=91k\frac{J}{k}g($note that we are talking about lower case $"u"$ here$).$ You may assume that changes

in kinetic and potential energy in this problem are negligible.

A$.$ Determine the mass of the air inside of the box in kg $.$ Be careful about your units when doing this

calculation and show your work if$/$when doing unit conversions.

B$.$ Determine the amount of work done in kJ$.$ Indicate the work as a positive number that is either

$"$in$"$ or "out."