Module 11: Applied Physical Sciences and Basic Electricity

1. An engine burns 2.4 liter of fuel each 12 minutes. The fuel has a specific gravity of 0.80, and a heating value of 42 MJ/kg. The engine has an efficiency of 33%. What is the brake horsepower of the engine?
   • a. 45 hp
   • b. 50 hp
   • c. 55 hp
   • d. 60 hp
2. What is the decrease in height of a 3.2 kg body whose kinetic energy increases from 28 J to 128 J as a result of moving downward along an inclined plane?
   • a. 3.19 m
   • b.4.20 m
   • c. 2.90 m
   • d. 5.28 m
3. An engine has an efficiency of 35%. It uses 6 gallons per hour. Gasoline has a heating value of 20300 Btu/lbm and specific gravity of 0.85. What is the power output of the engine?
   • a. 75.0 kW
   • b. 82.6 kW
   • c. 88.3 kW
   • d. 92.7 kW
4. A power 15 kW is supplied to the motor of a crane. The motor has an efficiency of 82%. With what constant speed does the crane lift a 1550 lbf weight?
   • a. 3.8 m/s
   • b. 4.2 m/s
   • c. 2.6 m/s
   • d. 1.8 m/s
5. A 5-lbm solid circular gear with a 3.8-in radius of gyration is turned by a motor running at 1400 rpm. What is the kinetic energy of the gear?
   • a. 167.3 ft-lb
   • b. 158.8 ft-lb
   • c. 161.2 ft-lb
   • d. 187.7 ft-lb
6. What is the kinetic energy of a 1200 lb motorcycle traveling at 70 mph?
   • a. 196405.9 ft-lb
   • b. 208111.3 ft-lb
   • c. 182771.0 ft-lb
   • d. 170077.8 ft-lb
7. Two particles collide, stick together, and continue their motion together. Each particle has a mass of 12 grams, and their respective velocities before collision were 18 m/s and 95 m/s. What is their common velocity after collision?
   • a. 50.3 m/s
   • b. 56.5 m/s
   • c. 68.7 m/s
   • d. 58.2 m/s
8. A car of mass m=1100 slugs accelerates in 15 seconds from rest at a constant rate to a speed of v=28 ft/s. What is the resultant force on the car due to this acceleration?
   • a. 1888.3 lbf
   • b. 2053.4 lbf
   • c. 2220.7 lbf
   • d. 1506.8 lbf
9. A 50 ton rail moving at 1.5 mph is instantaneously coupled to a stationary 80 ton rail car. What is the speed of the coupled cars?
   • a. 0.8813 mph
   • b. 0.6871 mph
   • c. 0.5770 mph
   • d. 0.4718 mph
10. The flow rate of water through a cast iron pipe is 4100 GPM. The pipe is 1.4 ft and the coefficient of friction f=0.0157. What is the pressure drop over a 260 ft length of pipe?
    • a. 99.5 psf
    • b. 84.6 psf
    • c. 82.2 psf
    • d. 90.3 psf
11. Three kilogram per second water enters the heater at 34 deg C and leaves at 95 deg C. Only 75% of the electrical energy is converted to heat energy. If the heater is connected to 2000 V source, find the current flowing through the heater.
    • a. 420.8 amp
    • b. 580.8 amp
    • c. 530.5 amp
    • d. 510.8 amp
12. A heater is rated 1200 watts. If the load resistance is 12 ohms, find the current flowing to the circuit.
    • a. 30 amp
    • b. 20 amp
    • c. 10 amp
    • d. 15 amp
13. A single phase AC circuit is connected to a 220 V source that draws 11 A current. If apparent power of the circuit is 2600 VA. Find the power factor of the circuit.
    • a. 85.2%
    • b. 88.8%
    • c. 76.1%
    • d. 93.1%
14. Two resistors 3 ohms and 12 ohms are connected in series and the combination is connected across the 450 V source. Find the voltage across the 3 ohms resistor.
    • a. 90V
    • b. 85V
    • c. 80V
    • d. 95V
15. An ideal transformer has 280 primary turns and 50 secondary turns. What is the secondary voltage if the primary voltage is 200 V?
    • a. 30.2V
    • b. 35.7V
    • c. 38.1V
    • d. 40.8V
16. The equivalent capacitance of capacitors C₁ and C₂ connected in series is 7.6 microfarad. If the capacitance C₁=9.8 microfarads, what is the capacitance C₂?
    • a. 30.2 μF
    • b. 33.9 μF
    • c. 38.4 μF
    • d. 42.8 μF
17. The voltage drop across a device is 230 V and the current drawn is 18 amps. What is the power rating of this device?
    • a. 3.5 hp
    • b. 4.5 hp
    • c. 5.5 hp
    • d. 6.5 hp
18. A charge of 630 coulombs passes through a wire every 18 seconds. What is the current in the wire?
    • a. 35 amps
    • b. 30 amps
    • c. 40 amps
    • d. 45 amps
19. If a car travels at 20 m/s and the track is banked at 9 deg, what is the smallest radius it can travel without skidding?
    • a. 200.0 m
    • b. 281.1 m
    • c. 234.5 m
    • d. 257.4 m
20. Traffic travels at 65 mph around a banked highway curve with a radius of 1800 ft. What banking angle is necessary such that friction will not be required to resist the centrifugal force?
    • a. 6.3 deg
    • b. 8.2 deg
    • c. 7.6 deg
    • d. 5.1 deg
21. A 28 inches long rod floats vertically in water. It has a 1.5 in2 cross section and has a specific gravity of 0.75. What length L is submerged?
    • a. 18 ft
    • b. 19 ft
    • c. 21 ft
    • d. 20 ft
22. A perfect venturi with throat diameter of 1.0 inches is placed horizontally in a pipe with 5 inches inside diameter. One hundred (100) lb of water flow through the pipe each second. What is the difference between the pipe and venture throat static pressure.
    • a. 432.7 psi
    • b. 457.2 psi
    • c. 580.0 psi
    • d. 591.2 psi
23. A cylindrical pipe with water flowing downward at 0.03 m³/s, having top diameter of 0.07 m, bottom diameter of 0.03 m and a height of 1.83 m. Find the pressure between the pipe.
    • a. 852.3 kPa
    • b. 901.1 kPa
    • c. 820.1 kPa
    • d. 880.1 kPa
24. Find the fraction of the volume of a solid object with specific gravity of 7.8 floats above the surface of a container of mercury?
    • a. 0.4265
    • b. 0.4626
    • c. 0.4879
    • d. 0.4779
25. A block of wood 0.5 m x 0.5 m x “y” meters in dimension was thrown in the water it floats with 0.16 m projecting above the water surface. The block was thrown into a container of liquid having a specific gravity of 0.92 and it floats with 0.13 m projecting above the liquid surface. Find the value of “y” and the specific gravity of the block, respectively.
    • a. 0.5049 m
    • b. 0.6481 m
    • c. 0.7681 m
    • d. 0.8817 m

Answer Key (Handwritten)