Topic : Mechanics
Questions 1 to 25: Select the best answer to each question. Note that a question and its answers may be split across a page break, so be sure that you have seen the entire question and all the answers before choosing an answer.
1. Oil flows upward in the wick of a lantern because of the liquid property called
A. meniscusity.
B. capillarity.
C. viscosity.
D. density.
2. The metric unit of force is the
A. gram.
B. kilogram.
C. newton.
D. nanometer.
3. A car travels from Boston to Hartford in 4 hours. The two cities are 240 kilometers apart. What was the average speed of the car during the trip?
A. 960 km/hour
B. 36 km/hour
C. 60 km/hour
D. 4 km/hour
4. Within the metric system all units are based on the number
A. 1.
B. 1000.
C. 10.
D. 100.
5. A man standing on a bus remains still when the bus is at rest. When the bus moves forward and then slows down the man continues moving forward at the original speed. This is an example of the effect of
A. gravity.
B. velocity.
C. weight.
D. inertia.
6. A steel block has a volume of 0.08 m³ and a density of 7,840 kg/m³. What is the force of gravity acting on the block (the weight) in water?
A. 5,362.56 N
B. 6,700.56 N
C. 6,150.64 N
D. 7,600.18 N
7. An object has a mass of 120 kg on the moon. What is the force of gravity acting on the object on the moon?
A. 20 N
B. 12.24 N
C. 196 N
D. 1,176 N
8. A stone falls from a ledge and takes 8 seconds to hit the ground. The stone has an original velocity of 0 m/s. How tall is the ledge?
A. 313.6 meters
B. 39.2 meters
C. 1,254.4 meters
D. 78.4 meters
9. A machine is supplied energy at a rate of 4,000 W and does useful work at a rate of 3,760 W. What is the efficiency of the machine?
A. 97 percent
B. 92 percent
C. 96 percent
D. 94 percent
10. In which of the following units is acceleration expressed?
A. Newtons
B. Meters per second squared
C. Kilograms
D. Foot-pounds
11. The main difference between speed and velocity involves
A. gravity.
B. direction.
C. distance.
D. weight.
12. If an object has a mass of 20 kg, what is the force of gravity acting on it on earth?
A. 32.67 N
B. 1.96 kg
C. 196 N
D. 2.04 kg
13. A car with a mass of 2,000 kilograms is moving around a circular curve at a uniform velocity of 25 meters per second. The curve has a radius of 80 meters. What is the centripetal force on the car?
A. 15,625 N
B. 20,250 N
C. 703 N
D. 625 N
14. How much time should be allowed for a 605-mile car trip if the car will be traveling at an average speed of 55 miles per hour?
A. 11 hours
B. 10.5 hours
C. 8.75 hours
D. 9 hours
15. The acceleration of gravity is a constant equal to _______ meters per second squared.
A. 10.2
B. 8.4
C. 9.8
D. 7.6
16. When an automotive battery is fully charged, the sulfuric acid and water mixture will have a specific gravity of about
A. 2.5.
B. 1.0.
C. 1.3.
D. 0.15.
17. What is the kinetic energy of an object that has a mass of 30 kilograms and moves with a velocity of 20 m/s?
A. 6,000 J
B. 12,000 J
C. 2,940 J
D. 5,880 J
18. A naturally occurring force related to two bodies in motion is _______ force.
A. frictional
B. centripetal
C. centrifugal
D. gravitational
19. A tank with a flat bottom is filled with water to a height of 4 meters. What is the pressure at any point at the bottom of the tank? (You can ignore atmospheric pressure when calculating your answer.)
A. 4.0 kPa
B. 18.9 kPa
C. 39.2 kPa
D. 9.8 kPa
20. An object with a mass of 78 kilograms is lifted through a height of 6 meters. How much work is done?
A. 47.75 J
B. 764.4 J
C. 468 J
D. 4,586.4 J
21. What force is required to accelerate a body with a mass of 15 kilograms at a rate of 8 m/s²?
A. 120 N
B. 23 kg
C. 1.875 kg
D. 23 N
22. The orbits of planets being elliptical was one the planetary laws developed by
A. Copernicus.
B. Ptolemy.
C. Brahe.
D. Kepler.
23. If a small-diameter open glass tube is partially immersed in a vessel containing mercury, the surface of the mercury inside the tube will be
A. lower than the mercury in the vessel, and shaped like the inside of a bowl.
B. higher than the mercury in the vessel, and shaped like the outside of an umbrella.
C. higher than the mercury in the vessel, and shaped like the inside of a bowl.
D. lower than the mercury in the vessel, and shaped like the outside of an umbrella.
24. In a practical machine, the power output is _______ the power input.
A. larger than
B. multiplied by
C. equal to
D. smaller than
25. According to Ptolemy's model of the movement of celestial bodies,
A. the sun is the center of the universe.
B. the earth rotates around the moon.
C. the earth rotates around the sun.
D. planets orbit in circular paths around the earth