12/3/2024 11:27AM
ENGR 103 EXAM 2 Questions With Correct
Answers
A pressure gauge reads 195 kPa. What is the absolute pressure at this point in units of psi if the
local atmospheric pressure is 0.94 atm. - answer✔42.1 psi
A vacuum gauge connected to a tank reads 48 kPa at a location where atmospheric pressure is
13.8
psi. What is the absolute pressure in units of kPa? - answer✔47.1 kPa
A force of 300 lbf is applied to the piston of a cylinder, compressing the gas within the cylinder.
The
piston has a radius on 15 in. If the local atmospheric pressure is 0.98 atm, what is the absolute
pressure inside the cylinder in psi? - answer✔14.8 psi
The temperature of a mixture is raised from 30°C to 56°C. What is the temperature change of the
mixture in units of °F, °R, and K? - answer✔26 K 46.8°F 46.8°R
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12/3/2024 11:27AM
If a mixture has a temperature change of 26K and has a specific heat of 4.912 kJ/kg-K, how
much energy did it take to raise the temperature that amount? Assume mass = 1 kg. -
answer✔128 kJ
An object is dropped off a balcony and reaches a maximum speed of 45 ft/s before hitting the
ground. How high is the balcony above the ground? - answer✔31.4'
A 70 kg person is standing at the edge of a diving platform. The PE of the person is 6800 J. If he
steps off the platform and freefalls, what is the velocity of the person right before he hits the
water? - answer✔13.9 m/s
A 165 lbm person climbs a stairway consisting of 160 stairs, each with a vertical rise of 8 inches.
How much work does this person do against gravity? - answer✔17600 ft lb
A spring is compressed 2 inches from its at-rest position. The spring is then compressed an
additional 3 inches. If the spring constant is 2600 N/cm, find the total work done in compressing
the spring in units of kJ. - answer✔2100 J = 2.10 kJ
During a time interval of 1 hour, a heat engine absorbs 360 MJ of energy from a high-
temperature
source while rejecting 40 KW to a low-temperature sink. How much power does the heat engine
produce? What is the thermal efficiency of the heat engine? - answer✔Eff = 60% 60 kW