front 1 A scientific statement that can never be changed is a scientific
| back 1 E) None of the above choices are correct. |
front 2 As an object falls
| back 2 A) its velocity increases
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front 3 Whirl a rock at the end of a string on an ice-covered pond and it follows a circular path. If the string breaks, the tendency of the rock is to
| back 3 A) travel in a straight line |
front 4 When you yank a table cloth out from under your dishes you are demonstrating
| back 4 B) inertia |
front 5 What is the acceleration of a freely falling object?
| back 5 A) 10 m/s^2 |
front 6 A package falls out of an airplane that is traveling at 300m/s. Neglecting air resistance, what is its horizontal velocity before hitting the ground?
| back 6 B) equal to 300m/s |
front 7 A disco ball falls from the midpoint of the ceiling of a moving van. It lands
| back 7 C) directly below the midpoint |
front 8 If you run out of gas while driving you don't come to a sudden stop. Why?
| back 8 A) inertia |
front 9 According to Newton's laws a train in motion would continue moving with its engines off. Why don't we observe this
| back 9 C) friction |
front 10 A moving object must have a change of
| back 10 B) position |
front 11 If a spaceship accelerating in outer space runs out of fuel it
| back 11 B) no longer accelerates |
front 12 If no external forces act on an object it will
| back 12 B) continue moving with the same velocity |
front 13 The last instant just before an airplane crashes a passenger jumps out the door and falls only two feet to the ground. The passenger is
| back 13 D) probably hurt of killed |
front 14 According to Newton’s law of inertia, the result of walking much of the day is similar to tightening the head of a hammer when its handle hits a solid surface so that we are actually a little bit shorter in the
| back 14 A) morning |
front 15 A sheet of paper can be withdrawn from under a container of milk without toppling it if the paper is jerked quickly.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
| back 15 D) the milk carton has inertia. |
front 16 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
| back 16 D) always have forces that oppose their motion |
front 17 A girl and a boy pull in opposite directions on strings attached to each end of a spring balance. Each child exerts a force of 20N. What will the reading on the spring balance be?
| back 17 C) 20 N |
front 18 A person standing on a scaffold lowers an object of weight 250N by means of a rope, at constant speed. If the weight of the rope is negligible, the force that the person exerts is …
| back 18 B) equal to 250N |
front 19 A passenger not wearing a safety belt hits the windscreen of a car in a head-on collision. This is an illustration of …
| back 19 A) Newton's First Law |
front 20 Galileo used an incline plane to effectively
| back 20 C) slow down the acceleration of gravity |
front 21 Which is not a vector
| back 21 A) speed |
front 22 An airplane flies at 100km/hr is still air. If it flies into a 10km/hr headwind, its ground speed will be
| back 22 C) 90 |
front 23 A car maintains a velocity of 45km/hr for 15 seconds, its acceleration is
| back 23 D) 0m/s^2 |
front 24 8 seconds after falling from rest the speed of a rock is
| back 24 C) 80m/s |
front 25 If an object moves at a constant acceleration, its velocity must
| back 25 B) change by the same amount each second |
front 26 A ball is tossed upward, reaches its highest point and then falls back down. Its acceleration is
| back 26 D) always downward |
front 27 At one instant a ball is falling at 40m/s, after one second it is falling at
| back 27 C) 50 |
front 28 Each second that an object falls the distance it covers is
| back 28 A) increasing |
front 29 A ball is thrown up at 35m/s, to get to the highest point takes
| back 29 C) 3.5s |
front 30 When a rock is thrown straight upward, at its highest point
| back 30 A) its velocity is zero |
front 31 Distance is to displacement as
| back 31 B) speed is to velocity |
front 32 When you look at the speedometer in a moving car, you can see the car's __________.
| back 32 A) instantaneous speed |
front 33 A ball is thrown straight up. At the top of its path its acceleration is __________.
| back 33 C) about 10 m/s to power of (2) |
front 34 In the absence of air resistance, objects fall at constant __________.
| back 34 A) acceleration with each successive second |
front 35 As an object falls freely in a vacuum, its __________.
| back 35 D) acceleration remains constant |
front 36 A car accelerates at 2 m/s to power of (2). Assuming the car starts from rest, how much time does it need to accelerate to a speed of 30 m/s?
| back 36 B) 15 seconds |
front 37 When a basketball player jumps to make a shot, once the feet are off the floor, the jumper's acceleration __________.
| back 37 D) is always g |
front 38 Suppose you take a trip that covers 240 km and takes 4 hours to make. Your average speed is __________.
| back 38 B) 60 km/h |
front 39 Suppose you are in a car that is going around a curve. The speedometer reads a constant 30 miles per hour. Which of the following is true?
| back 39 D) Your acceleration is constant |
front 40 If you drop a feather and a coin at the same time in a vacuum tube, which will reach the bottom of the tube first?
| back 40 D) Neither, they will both reach the bottom at the same time |
front 41 A ball is thrown upwards and caught when it comes back down. In the absence of air resistance, the speed of the ball when caught would be __________.
| back 41 C) the same as the speed it had when thrown upwards |
front 42 An object travels 8 meters in the first second of travel, 8 meters again during the second second of travel, and 8 meters again during the third second. Its acceleration is __________.
| back 42 A) 0 m/s to power of (2) |
front 43 If a freely falling object were somehow equipped with a speedometer, its speed reading would increase each second by __________.
| back 43 B) about 10 m/s |
front 44 Suppose a car is moving in a straight line and steadily increases its speed. It moves from 35 km/h to 40 km/h the first second and from 40 km/h to 45 km/h the next second. What is the car's acceleration?
| back 44 A) 5 km/h s |
front 45 A ball is thrown straight up with an initial speed of 10 m/s. At the top of its path its instantaneous speed is __________.
| back 45 A) 0 m/s |
front 46 A ball tossed vertically upward rises, reaches its highest point, and then falls back to its starting point. During this time the acceleration of the ball is always __________.
| back 46 D) directed downward |
front 47 True or False
| back 47 False
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front 48 True or False
| back 48 True |
front 49 True or False
| back 49 True |
front 50 True or False
| back 50 False
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front 51 True or False
| back 51 True |
front 52 True or False
| back 52 False
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front 53 True or False
| back 53 True |
front 54 True or False
| back 54 False
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front 55 True or False
| back 55 False
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front 56 True or False
| back 56 False
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front 57 Why does time enter twice the SI unit for acceleration? | back 57 Time enters twice in the SI unit for acceleration because it is used once for the time it takes to change position and again for the time it takes to change velocity |
front 58 Explain how it is possible to accelerate without changing speed. | back 58 Since acceleration means that an object is either changing speed or changing direction it is possible to accelerate without changing speed by simply changing direction. |
front 59 If the line on a p-t graph is curved, what is the object doing? How would this same kind of motion look on a v-t graph? Sketch both graphs and label everything. | back 59 If the line on a p-t graph is curved, the object is accelerating. On a v-t graph this would look like a diagonal line moving up and to the right. Here is a sketch of what the graph should look like: |
front 60 What is the acceleration of a car that goes from rest to 90 km/h in 6.0 seconds? | back 60 a = ? km/h
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front 61 If you drop a stone down a deep well and 3.7 seconds later you hear it splash in the water how deep must the well be? (Ignore the time it takes for the sound to travel up the well. | back 61 t = 3.7 s
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front 62 What is the velocity of a cheetah that runs 130 m in 8.0 s?+ | back 62 d = 130 m
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front 63 Which has the greater mass?
| back 63 A) an automobile battery |
front 64 A kilogram is a measure of an object's
| back 64 A) mass |
front 65 Your weight is
| back 65 B) the gravitational attraction force between you and the Earth |
front 66 Compared to the mass of a certain object on Earth, the mass of the same object on the moon is
| back 66 B) the same |
front 67 A force is a vector quantity because it has both
| back 67 C)magnitude and direction |
front 68 If an object's mass is decreasing while a constant force is applied to the object, the acceleration
| back 68 C) increases |
front 69 A 10-N falling object encounters 4 N of air resistance. The net force on the object is
| back 69 C) 6N |
front 70 A heavy block at rest is suspended by a vertical rope. When the block is accelerated upward by the rope, the rope tension
| back 70 A) increases |
front 71 A girl pulls on a 10-kg wagon with a constant horizontal force of 30 N. If there are no other horizontal forces, what is the wagon's acceleration in meters per second per second?
| back 71 B) 3 |
front 72 When a falling object has reached its terminal velocity, its acceleration is
| back 72 A) zero |
front 73 A ball is thrown vertically into the air. Because of air resistance, its speed when it returns to its starting level compared with its initial speed is
| back 73 C) less |
front 74 A skydiver's terminal velocity will be greatest if she falls
| back 74 B) head first |
front 75 Wherever there is an action force, there must be a reaction force which
| back 75 C) is exactly equal in magnitude |
front 76 A player hits a ball with a bat. The action force is the impact of the bat against the ball. The reaction to this force is the
| back 76 B) force that the ball exerts on the bat |
front 77 The attraction of a person's body toward the Earth is called weight. The reaction to this force is
| back 77 B) the person's body pulling on the Earth |
front 78 The Earth pulls on the moon. Similarly the moon pulls on the Earth, evidence that
| back 78 B) these two pulls comprise an action-reaction pair |
front 79 A automobile and a baby carriage traveling at the same speed collide head-on. The impact force is
| back 79 A) the same for both |
front 80 A Mack truck and a Volkswagen have a head-on collision. The vehicle that undergoes the greatest change in velocity will be the
| back 80 A) Volkswagen |
front 81 Joe pushes Bill, who is asleep. Bill
| back 81 A) pushes Joe equally hard even without waking up |
front 82 A horse exerts 500 N of force on a heavy wagon. The wagon pulls back on the horse with an equal force. The wagon still accelerates because
| back 82 D) there is a net force on the wagon |
front 83 A karate chop delivers a blow of 3000 N to a board that breaks. The force that acts on the hand during this event is
| back 83 A) 3000N |
front 84 A piece of rope is pulled by two people in a tug-of-war. Each pulls with 400 N of force. What is the tension in the rope?
| back 84 D) 400N |
front 85 Two people, one twice as massive as the other, attempt a tug-of- war with 12 meters of massless rope on frictionless ice. After a brief time, they meet. The heavier person slides a distance of
| back 85 D) 4m |
front 86 A 40kg vehicle is traveling in outer space at a speed of 30 m/s . It can be stopped by applying a constant force of 200 N for
| back 86 D) 6s |