General Physics Study Guide

Ch4&5
1.All except one of the following require the application of a net force. Which one is the exception? | Changing an object's speed without changing its direction of motion | | Changing an object's direction of motion without changing its speed | | Maintaining an object in uniform circular motion | | Changing an object from a state of rest to a state of motion | | Maintaining an object in motion at a constant velocity |

2.The force that accelerates a car on a level road is exerted by the | motor. | | gears. | | gasoline. | | road. | | tires. |

3.The frictional force, due to air resistance, acting on an object is always | in the upward direction. | | in the direction of the object's motion. | | in the opposite direction to the object's motion. | | greater than the net force. | | smaller than object's weight. |

4. The erroneous idea that an object needs a force on it to keep moving even at constant velocity was held by | Newton. | | Galileo. | | Aristotle. |

5. Two pieces of kryptonite, #1 and #2, have identical masses, but the net force applied to #1 is 20 N and to #2 is 400 N. The acceleration | of each piece of kryptonite is the same. | | depends on the weight of each piece of kryptonite. | | of #2 is larger. | | of #1 is larger. |

6. A car rounds a curve while maintaining constant speed. The correct statement is: | The velocity of the car is constant. | | The velocity of the car is zero. | | The acceleration of the car is zero. | | No net force acts on the car. | | A net force acts upon the car. |

7. A block of mass 5.0 kg is acted upon by a single force, producing an acceleration of 2.0 m/s2. The force has a value of | 10 N. | | 5.0 N. | | 0.5 N. | | 2.5 N. |

8. A 10.0 kg block on a smooth horizontal surface is acted upon by two forces: a horizontal force of 70 N acting to the right and a horizontal force of 30 N to the left. The acceleration of the block will be | 10.0 m/s2 to the right. | | 2.3 m/s2 to the right. | | 210.0 m/s2 to the right. | | 4.0 m/s2 to the right. |

9. A crate is acted upon by a net force of 100 N. An acceleration of 5.0 m/s2 results. The weight of the crate is | 196 N. | | 20 N. | | 196 lb. | | 0 |
10. An elevator of mass 500 kg is caused to accelerate upward at 4.0 m/s2 by a force in the cable. What is the force exerted by the cable? | 2,000 N | | 4,900 N | | zero | | 2,900 N | | 6,900 N |

11. A certain force causes a 50 kg person to accelerate at 1.0 m/s2. The same force applied to a 75-kg person would cause | a greater acceleration. | | a smaller acceleration. | | the same acceleration. |

12. A dog weighs 250 N. What is his approximate weight in pounds (lb)? | 25 lb. | | 100 lb. | | 55 lb. | | 250 lb. | | 32 lb. |
13. Your mass is 50 kg. Suppose you are standing on a scale in an elevator that is approaching a top floor and decreasing its speed at the rate of 2 m/s every second. What would be the reading on the scale? | 490 N. | | 0. | | 590 N. | | 100 N. | | 390 N. |

14.

Three forces act on the object in the sketch. In what direction will the object move? | To the left. | | Upward. | | To the right. | | To the left and up. | | To the right and up. |

15. A father and his young daughter are on very clean ice, so there is very little friction (the father has more mass than the daughter). The father pushes his daughter forward and she slides away at a speed of 3 m/s. The father's velocity is | smaller than 3 m/s in the same direction as his daughter. | | 3 m/s in the same direction as his daughter. | | smaller than 3 m/s in the opposite direction as his daughter. | | zero. | | 3 m/s in the opposite direction as his daughter. |

16. Earth's gravity attracts a person with a force of 120 lbs. The force with which the Earth is attracted towards the person is | small but not zero. | | 120 lbs. | | billions and billions of tons. | | zero. |
17. An object weighs 20 newtons on Earth. What is its approximate mass? | 640 kg. | | 2 kg. | | 20 g. | | 10 kg. | | 196 kg. |

18. After 1 second, a ball dropped from rest will have fallen | 19.6 m. | | 4.9 m. | | 1.0 m. | | 9.8 m. | | 2.45 m. |
19. A 10 pound iron ball and a 2 pound iron ball are dropped simultaneously from a height of 100 meters. Neglecting air resistance, which ball will reach the ground first? | The 2 lb ball. | | The 10 lb ball. | | They will reach the ground at the same time. |
20. Consider two blocks, one made of wood and the other of lead. They have the same dimensions but the lead is much more massive. If they are dropped and fall long enough to reach terminal velocity, which block experiences a larger force from air resistance? | The force on each is equal. | | The wood block. | | It isn't important because air resistance can be ignored. | | The lead block. |
21. A physics professor places a soda pop can on the table and asks a student to identify the forces acting upon the can and the directions of each force. The two forces acting on the soda pop can are | the upward normal force from the table and the downward force of gravity on the can. | | weight force from Earth and downward normal force from the bottom surface of the can. | | the upward force of the table on the can and the normal force of the table on the can. | | the weight force of the can on Earth through the table, since the table is rigid, and the weight force from Earth on the can. |

22. When an object is at rest, it might have several forces acting on it. However, | the forces are all in the same direction. | | the forces balance out to net force of zero. | | there can only be one force opposite gravity, since weight depends on mass. | | dynamic equilibrium can never be achieved except in the total absence of all forces. |

23. In the trajectory of a thrown object, like a baseball, the weight force is always downward. However, the force of air resistance is always | upward. | | horizontal. | | perpendicular to the trajectory. | | tangent to the trajectory and in the direction opposite the velocity. |

24. Which of the following is NOT a vector? | Velocity. | | All of these choices are correct. | | Acceleration. | | Weight. | | Mass. |

25. A calculus book weighing 20 N is held on the floor of a classroom. The reaction to the force of the floor on the book is a force of | 0 N. | | 20 N exerted by the book on the Earth. | | 10 N exerted by the floor on the hand. | | 10.2 m/s2 exerted by the Earth on the book. |

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Ch 2

1.Whereas Aristotle relied on logic in explaining nature, Galileo relied on | experiment. | | mathematics. | | logic also. | | patterns. |
2.The scientist to first introduce the concept of inertia was | Newton. | | Aristotle. | | Galileo. | | Copernicus. |

3.Galileo's interpretation of motion differed from Aristotle's in that Galileo emphasized | time rates. | | the role of distance in describing motion. | | the acceleration of free fall. | | all of these | | none of these |

4.A sheet of paper can be withdrawn from under a container of milk without toppling it if the paper is jerked quickly. This best demonstrates that | gravity tends to hold the milk carton secure. | | there is an action-reaction pair of forces. | | the milk carton has inertia. | | the milk carton has no acceleration. | | none of these |
5.An object in mechanical equilibrium is an object | having no acceleration. | | moving with constant velocity. | | at rest. | | all of these |

6.When you stand at rest on a pair of bathroom scales, the readings on the scales will always | each be half your weight. | | add up to equal your weight. | | each equal your weight. |

7.Hang from a pair of gym rings and the upward support forces of the rings will always | each equal your weight. | | add up to equal your weight. | | each be half your weight. |

8.A man weighing 800 N stands at rest on two bathroom scales so that his weight is distributed evenly over both scales. The reading on each scale is | 400 N. | | 800 N. | | 200 N. | | none of these |

9.The force of friction on a sliding object is 10 N. The applied force needed to maintain a constant velocity is | less than 10 N. | | 10 N. | | more than 10 N. |
10.A 300-kg bear grasping a vertical tree slides down at constant velocity. The friction force between the tree and the bear is
Question options: | 300 N. | | 30 N. | | 3000 N. | | more than 3000 N. |
11.A package falls off a truck that is moving at 30 m/s. Neglecting air resistance, the horizontal speed of the package just before it hits the ground is | less than 30 m/s but larger than zero. | | zero. | | more than 30 m/s. | | about 30 m/s. | | More information is needed for an estimate. |

12.A truck is moving at constant velocity. Inside the storage compartment, a rock is dropped from the midpoint of the ceiling and strikes the floor below. The rock hits the floor | ahead of the midpoint of the ceiling. | | exactly below the midpoint of the ceiling. | | behind the midpoint of the ceiling. | | More information is needed to solve this problem. | | none of these |

13.If your automobile runs out of fuel while you are driving, the engine stops but you do not come to an abrupt stop. The concept that most explains why is | acceleration. | | inertia. | | gravity. | | resistance. |

14.According to Newton's law of inertia, a railroad train in motion should continue going forever even if its engine is turned off. We never observe this because railroad trains | move too slowly. | | are much too heavy. | | always have forces that oppose their motion. | | must go up and down hills. |

15.Whirl a rock at the end of a string and it follows a circular path. If the string breaks, the tendency of the rock is to | continue to follow a circular path. | | revolve in a smaller circle. | | follow a straight-line path. | | increase its speed. |

16.When a rocket ship accelerating in outer space runs out of fuel, it | accelerates for a short time, then slows down to a constant velocity. | | no longer accelerates. | | accelerates for a short time, slows down, and eventually stops. |

17.If no external forces are acting on a moving object, it will | move slower and slower until it finally stops. | | continue moving at the same speed. | | continue moving at the same velocity. |

18.Galileo's use of inclined planes allowed him to effectively | eliminate friction. | | slow down the acceleration of free fall. | | increase the acceleration beyond that of free fall. | | eliminate the acceleration of free fall. |

19.A common experience is to find that a steady pull is required to keep an object moving, even on a level surface with friction present. Analyzing this experience in light of the laws of motion, the accepted conclusion is that | the object is really accelerating but it is not apparent. | | a frictional force exactly opposes your pull and the first law applies. | | the laws of motion only apply when you start pulling or stop. | | your pull is canceled by the third law reaction force. | | the laws of motion do not apply where there is friction. |

20.The erroneous idea that an object needs a force on it to keep moving even at constant velocity was held by | Newton. | | Aristotle. |

21The main reason that physics is perceived to be difficult is because people think that | all of its concepts seem incompatible with our everyday experience. | | the laws of physics are often shown to be wrong. | | math is required to understand its ideas. | | it frequently changes its explanations of common occurrences. |

22.Physics is considered the "Fundamental Science" because | if a person understands physics, he or she does not need to know anything about other sciences. | | physics offers the only exact explanations of how things work; other sciences only provide approximate answers. | | the ideas and concepts of physics are an important part of the foundation of other sciences. | | it makes the most use of mathematics. |

23.In order to gain a more scientific worldview, the student is encouraged to | perform simple experiments at home. | | perform experiments, but only in the laboratory. | | refrain from experiments; they are all too complicated. | | consult the oldest books available. |

24.When a scientist wants to strengthen a theory, she can make predictions of measurable events. The theory becomes stronger when | she and other scientists observe and measure the events, and they find that the events agree with the prediction. | | the theory is voted upon in a democratic process. | | the measurement process goes against the prediction, thereby proving the theory valid. | | her supervisor gives the prediction government funding. |

25When trying to make sense of the universe, it is useful to study everyday physics of things you see in your hometown, even in your own kitchen, because | when you finish, you can eat the experiment. | | we expect the same laws govern physics in your hometown and everywhere else in the universe. | | only astrology governs the planets. | | no one knows any of the physical principles that govern the universe outside our planet, Earth. |

CH 3

1.Which of the curves in the figure best shows the speed of an object falling from rest without air friction? | C | | D | | A | | B |

2. If you drop a ball in the absence of air resistance, it accelerates downward at 9.8 m/s2. If instead you throw the ball upward, then its acceleration after release is | greater than 9.8 m/s2. | | less than 9.8 m/s2. | | equal to 9.8 m/s2. |

3. You toss a ball straight up in the air. At the highest point, the ball's | velocity is zero and the acceleration is upward. | | velocity and acceleration are zero. | | velocity is zero and the acceleration is downward. | | acceleration is zero but not its velocity. |

4. The acceleration due to the Earth's gravity, in English units, is 32 ft/s2. In the absence of air friction, a ball is dropped from rest. Its speed on striking the ground is exactly 60 miles/hr. For what time interval was the ball falling? (There are 5280 feet in one mile.) | 6.1 s. | | 5 s. | | 2.75 s. | | 1.875 s. |
5.The acceleration due to the Earth's gravity, in English units, is 32 ft/s2. In the absence of air friction, a ball is dropped from rest. Its speed on striking the ground is exactly 88 ft/s. From what height was the ball dropped? | 165 ft. | | 242 ft. | | 121 ft. | | 88 ft. |

6.In order to find the depth of a well, you drop a stone into it and time its fall. It hits the water after falling for 1.7 s. The depth of the well is about | 5 m. | | 20 m. | | 14 m. | | 10 m. |

7.A 10-kg object dropped from a certain window strikes the ground in 2.0 s. Neglecting air resistance, a 5-kg object dropped from the same window strikes the ground in | 4.0 s. | | 2.0 s. | | 1.0 s. | | 8.0 s. |

8.An object rises at 5 m/s under the influence of gravity only. One second later the object is | neither rising nor falling. | | falling at 5 m/s. | | rising at 5 m/s. | | rising at 4 m/s. |

9.A ball is thrown straight up. It reaches its highest point and then falls back. Which of the following is the correct statement? | Throughout its motion, the ball's acceleration is zero. | | At the highest point in its motion, the ball's acceleration is zero. | | Throughout its motion, the ball's velocity is zero. | | At the highest point in its motion, the ball's velocity is zero. | | At the highest point in its motion, the ball's velocity and acceleration are zero. |

10.After 1 second, a ball dropped from rest will have fallen | 1.0 m. | | 4.9 m. | | 19.6 m. | | 9.8 m. | | 2.45 m. |

11.A man standing on a bridge throws a stone horizontally with a speed of 20 m/s. The stone hits the water below 3 s later. The bridge is | 60 m high. | | 45 m high. | | 30 m high. | | 20 m high. |

12.A car traveling at constant speed | travels more distance in a second the longer the car travels. | | can change direction. | | cannot go uphill. | | does not turn. |

13.The following quantities relate to the rate of change of position. Which pair will always have the same magnitude? | Average velocity and instantaneous velocity. | | Average speed and average velocity. | | Average speed and instantaneous speed. | | Instantaneous speed and instantaneous velocity. |

14.The acceleration of a body cannot be zero at a point where | the instantaneous velocity is zero. | | the instantaneous velocity is positive but decreasing. | | none of these. | | the average velocity is positive. |

15.Initially you are driving at 55 mi/hr. If you come to rest in 7.5 s while traveling 450 ft, your average speed is | 0.016 ft/s. | | 55 mi/hr. | | 120 ft/s. | | 60 ft/s. |

16.If your average speed for a 3-hr trip is 45 mi/hr, the distance traveled is | 15 mi. | | 202.5 mi. | | 45 mi. | | 135 mi. |

17.In a speedometer test zone on a highway, you drive 5 miles in 6 minutes. During the test, your speedometer reading is 55 mi/hr. Your speedometer reading is | equal to your actual speed. | | lower than your actual speed. | | higher than your actual speed. |

18If your car can accelerate at 9.8 m/s2, you can go from zero to 60 mi/hr in about | 0.37 s. | | 2.74 s. | | 13.7 s. | | 2.34 s. |

19.In order to go from rest to 100 m/s in 20 s, a jet must be able to accelerate at | 5 m/s2. | | 100 m/s2. | | 10 m/s2. | | 20 m/s2. |

20.A car starts from rest and reaches 20 m/s in 10 seconds. The average acceleration of the car in m/s2 is | 4.0. | | zero. | | 10.0. | | 2.0. | | 1.0. |

21.Which of the following is not an appropriate unit for measuring acceleration? | m/s. | | km/min/s. | | miles/hr/s. | | m/min2. | | ft/s2. |

22.Which of the following quantities relating to motion is not a vector? | Displacement. | | Acceleration. | | All of these are vectors. | | Speed. | | Velocity. |

23.A quantity that is a measure of how the distance traveled changes with time is | speed. | | acceleration. | | displacement. | | momentum. | | velocity. |

24.A body travels at an initial speed of 1.5 m/s. Given a constant acceleration of 0.2 m/s2, what is the speed of the body at time 25 seconds later? | 4.5 m/s. | | 5.0 m/s. | | 2.4 m/s. | | 2.6 m/s. | | 6.5 m/s. |

25.A sprinter moving at 10 m/s slows down at a rate of 1.4 m/s2. How fast is the runner moving after 3 seconds? | 0 m/s. | | 5.8 m/s. | | 3.7 m/s. | | 16.3 m/s. |