Student Name: _________________________________________________________________
NSE/ME 311
Homework 1
Fall 2023
Instructions:
Please neatly complete the following questions. Scan or print it as a PDF file and upload your
completed work to Homework 1 on Canvas.
2.3.
An object of mass 1000 kg, initially having a velocity of 100 m /s, decelerates to a final
velocity of 20 m/s. What is the change in kinetic energy of the object, in kJ?
2.4.
An airplane whose mass is 5000 kg is flying with a velocity of 150 m/s at an altitude of
10,000 m, both measured relative to the surface of the earth. The acceleration of gravity
can be taken as constant at g=9.78 m/s2.
(a)
Calculate the kinetic and potential energies of the airplane, both in kJ.
(b)
If the kinetic energy increased by 10,000 kJ with no change in elevation, what
would be the final velocity, in m/s?
2.37.
As shown in the following figure, 5 kg of steam
contained within a piston– cylinder assembly
undergoes an expansion from state 1, where the
specific internal energy is u1=2709.9 kJ/kg, to state 2,
where u2=2659.6 kJ/kg. During the process, there is
heat transfer to the steam with a magnitude of 80 kJ.
Also, a paddle wheel transfers energy to the steam by
work in the amount of 18.5 kJ. There is no significant
change in the kinetic or potential energy of the steam.
Determine the energy transfer by work from the
steam to the piston during the process, in kJ.
2.42.
Two kilograms of air is contained in a rigid well-insulated tank with a volume of 0.6 m3. The
tank is fitted with a paddle wheel that transfers energy to the air at a constant rate of 10 W for
1 h. If no changes in kinetic or potential energy occur, determine:
(a)
the specific volume at the final state, in m3/kg.
(b)
the energy transfer by work, in kJ.
(c)
the change in specific internal energy of the air, in kJ/kg.