ENGR 103 EXAM 2 WITH
COMPLETE SOLUTION
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
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
A heat engine absorbs 45 MW from a 252°C combustion chamber and rejects
22.0 MW to the
atmosphere at 32°C. Find the actual thermal efficiency and the Carnot
thermal efficiency of the
COMPLETE SOLUTION
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
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
A heat engine absorbs 45 MW from a 252°C combustion chamber and rejects
22.0 MW to the
atmosphere at 32°C. Find the actual thermal efficiency and the Carnot
thermal efficiency of the
