Newton's Laws of Motion © 2013 Pearson Education, Inc.

The first to introduce the concept of inertia was Galileo. Newton. both. neither. Answer: C) both. © 2013 Pearson Education, Inc.

The first to introduce the concept of inertia was Galileo. Newton. both. neither. Comment: Galileo discovered the concept and Newton elevated it to his first law of motion. Answer: C) both. © 2013 Pearson Education, Inc.

If gravity between the Sun and Earth suddenly vanished, Earth would move in a curved path. a straight-line path. an outward spiral path. an inward spiral path. Answer: B) a straight-line path. © 2013 Pearson Education, Inc.

If gravity between the Sun and Earth suddenly vanished, Earth would move in a curved path. a straight-line path. an outward spiral path. an inward spiral path. Answer: B) a straight-line path. © 2013 Pearson Education, Inc.

Seat belts and air bags in a car are mostly linked to the effects of Newton's first law. second law. third law. law of gravity. Answer: A) first law. © 2013 Pearson Education, Inc.

Seat belts and air bags in a car are mostly linked to the effects of Newton's first law. second law. third law. law of gravity. Comment: Although Newton's three laws of motion are at play, the first law is most applicable. Answer: A) first law. © 2013 Pearson Education, Inc.

The net force on any object in equilibrium is zero. 10 meters per second squared. equal to its weight. none of the above. Answer: A) zero. © 2013 Pearson Education, Inc.

The net force on any object in equilibrium is zero. 10 meters per second squared. equal to its weight. none of the above. Answer: A) zero. © 2013 Pearson Education, Inc.

When standing in the aisle of a smoothly riding bus, you drop a coin from above your head. The falling coin will land at your feet. slightly in front of your feet. slightly in back of your feet. at a location not listed above. Answer: A) at your feet. © 2013 Pearson Education, Inc.

When standing in the aisle of a smoothly riding bus, you drop a coin from above your head. The falling coin will land at your feet. slightly in front of your feet. slightly in back of your feet. at a location not listed above. Explanation: The horizontal velocity of the coin remains the same while it falls. Answer: A) at your feet. © 2013 Pearson Education, Inc.

Consider a cart with a ball resting in its middle Consider a cart with a ball resting in its middle. When you quickly jerk the cart forward, the front of the cart hits the ball. back of the cart hits the ball. ball remains in the middle as the cart moves forward. above can all occur depending on how quickly the cart is pulled. Answer: B) back of the cart hits the ball. © 2013 Pearson Education, Inc.

Consider a cart with a ball resting in its middle Consider a cart with a ball resting in its middle. When you quickly jerk the cart forward, the front of the cart hits the ball. back of the cart hits the ball. ball remains in the middle as the cart moves forward. above can all occur depending on how quickly the cart is pulled. Explanation: Relative to the ground, the ball tends to remain at rest while the cart moves beneath it. Hence, the back of the cart hits the ball. Answer: B) back of the cart hits the ball. © 2013 Pearson Education, Inc.

When a 10-kg block is simultaneously pushed eastward with 20 N and westward with 15 N, the net force on the block is 35 N west. 35 N east. 5 N west. 5 N east. Answer: D) 5 N east. © 2013 Pearson Education, Inc.

When a 10-kg block is simultaneously pushed eastward with 20 N and westward with 15 N, the net force on the block is 35 N west. 35 N east. 5 N west. 5 N east. Answer: D) 5 N east. © 2013 Pearson Education, Inc.

When a 10-kg block is simultaneously pushed eastward with 20 N and westward with 15 N, the acceleration of the block is 0.5 m/s2 east. 0.5 m/s2 west. 0.5 m/s2 east–west. none of the above. Answer: A) 0.5 m/s2 east. © 2013 Pearson Education, Inc.

When a 10-kg block is simultaneously pushed eastward with 20 N and westward with 15 N, the acceleration of the block is 0.5 m/s2 east. 0.5 m/s2 west. 0.5 m/s2 east–west. none of the above. Explanation: Note the mass of a 10-N block is about 1 kg. Then a = F/m = (20 N – 15 N)/1 kg = 0.5 m/s2. Answer: A) 0.5 m/s2 east. © 2013 Pearson Education, Inc.

The connection between mass, acceleration, and force is embodied in Newton's first law. second law. third law. law of gravity. Answer: B) second law. © 2013 Pearson Education, Inc.

The connection between mass, acceleration, and force is embodied in Newton's first law. second law. third law. law of gravity. Comment: acceleration = force/mass. Answer: B) second law. © 2013 Pearson Education, Inc.

A cart is pushed and undergoes a certain acceleration A cart is pushed and undergoes a certain acceleration. Consider how the acceleration would compare if it were pushed with twice the net force while its mass increased by four. Then its acceleration would be one quarter. the same. twice. none of the above. Answer: D) none of the above. © 2013 Pearson Education, Inc.

A cart is pushed and undergoes a certain acceleration A cart is pushed and undergoes a certain acceleration. Consider how the acceleration would compare if it were pushed with twice the net force while its mass increased by four. Then its acceleration would be one quarter. the same. twice. none of the above. Explanation: Twice the force acting on four times the mass gives half the acceleration. So the acceleration would be half—none of the above. Answer: D) none of the above. © 2013 Pearson Education, Inc.

When the net force on a moving object remains at right angles to the velocity, speed decreases. increases. remains the same. none of the above. Answer: C) remains the same. © 2013 Pearson Education, Inc.

When the net force on a moving object remains at right angles to the velocity, speed decreases. increases. remains the same. none of the above. Explanation: At right angles, the object changes direction. With no component of force along its direction of motion, nochange in speed occurs. Answer: C) remains the same. © 2013 Pearson Education, Inc.

When you toss a rock straight upward, which is no longer present at the top of its path? Mass. Speed. Acceleration. All of the above. Answer: B) speed. © 2013 Pearson Education, Inc.

When you toss a rock straight upward, which is no longer present at the top of its path? Mass. Speed. Acceleration. All of the above. Explanation: It still has a force on it, mg, so a = F/m = mg/m = g. Only speed is zero at the top. Answer: B) speed. © 2013 Pearson Education, Inc.

A falling object that reaches terminal velocity continues to have speed. a nonzero net force. acceleration. all of the above. Answer: A) speed. © 2013 Pearson Education, Inc.

A falling object that reaches terminal velocity continues to have speed. a nonzero net force. acceleration. all of the above. Explanation: At terminal velocity, both net force and acceleration are zero. Answer: A) speed. © 2013 Pearson Education, Inc.

A heavy parachutist has a greater terminal speed compared with a light parachutist with the same size chute, because the heavier person has to fall faster for air resistance to match weight. is more greatly attracted by gravity to the ground below. has a greater air resistance. has none of the above. Answer: A) has to fall faster for air resistance to match weight. © 2013 Pearson Education, Inc.

A heavy parachutist has a greater terminal speed compared with a light parachutist with the same size chute, because the heavier person has to fall faster for air resistance to match weight. is more greatly attracted by gravity to the ground below. has a greater air resistance. has none of the above. Explanation: At terminal speed, both weight and air resistance have the same magnitude. To get that greater magnitude of air resistance, falling speed has to be greater for the heavier person. Answer: A) has to fall faster for air resistance to match weight. © 2013 Pearson Education, Inc.

When a 10-kg falling object encounters 10 N of air resistance, its acceleration is less than g. g. more than g. unknown—there is not enough information. Answer: A) less than g. © 2013 Pearson Education, Inc.

When a 10-kg falling object encounters 10 N of air resistance, its acceleration is less than g. g. more than g. unknown—there is not enough information. Explanation: Any object that encounters air resistance accelerates at less than g. Answer: A) less than g. © 2013 Pearson Education, Inc.

A soccer ball is kicked to a 30-m/s speed A soccer ball is kicked to a 30-m/s speed. While being kicked, the amount of force of the player's foot on the ball is less than the amount of force on the foot. the same as the amount of force on the foot. more than the amount of force on the foot. none of the above. Answer: B) the same as the amount of force on the foot. © 2013 Pearson Education, Inc.

A soccer ball is kicked to a 30-m/s speed A soccer ball is kicked to a 30-m/s speed. While being kicked, the amount of force of the player's foot on the ball is less than the amount of force on the foot. the same as the amount of force on the foot. more than the amount of force on the foot. none of the above. Explanation: Newton's third law, pure and simple. The speed of the ball is irrelevant. The amount of force on the ball and on the foot is the same. Answer: B) the same as the amount of force on the foot. © 2013 Pearson Education, Inc.

A karate chop delivers a blow of 3500 N to a board that breaks A karate chop delivers a blow of 3500 N to a board that breaks. The force that acts on the hand during this event is less than 3500 N. 3500 N. greater than 3500 N. none of the above. Answer: B) 3500 N. © 2013 Pearson Education, Inc.

A karate chop delivers a blow of 3500 N to a board that breaks A karate chop delivers a blow of 3500 N to a board that breaks. The force that acts on the hand during this event is less than 3500 N. 3500 N. greater than 3500 N. none of the above. Comment: Hence, the need for a strong hand! Answer: B) 3500 N. © 2013 Pearson Education, Inc.

Earth pulls on the Moon. Similarly, the Moon pulls on Earth, evidence that Earth and Moon are pulling on each other. Earth's and Moon's pulls comprise an action–reaction pair of forces. both of the above occur. neither of the above occur. Answer: C) both of the above occur. © 2013 Pearson Education, Inc.

Earth pulls on the Moon. Similarly, the Moon pulls on Earth, evidence that Earth and Moon are pulling on each other. Earth's and Moon's pulls comprise an action–reaction pair of forces. both of the above occur. neither of the above occur. Answer: C) both of the above occur. © 2013 Pearson Education, Inc.

The amount of air resistance on a 0 The amount of air resistance on a 0.8-N flying squirrel for terminal speed is less than 0.8 N. 0.8 N. more than 0.8 N. depends on the orientation of its body. Answer: B) 0.8 N. © 2013 Pearson Education, Inc.

The amount of air resistance on a 0 The amount of air resistance on a 0.8-N flying squirrel for terminal speed is less than 0.8 N. 0.8 N. more than 0.8 N. depends on the orientation of its body. Explanation: For terminal speed, net force must equal zero, no matter what the orientation of the squirrel's body. How great the terminal speed is, however, does depend on body orientation. But that's not the question asked. Answer: B) 0.8 N. © 2013 Pearson Education, Inc.

As a flying squirrel falls faster and faster through the air, air resistance increases. net force decreases. acceleration decreases. all of the above. Answer: D) all of the above. © 2013 Pearson Education, Inc.

As a flying squirrel falls faster and faster through the air, air resistance increases. net force decreases. acceleration decreases. all of the above. Answer: D) all of the above. © 2013 Pearson Education, Inc.

A tennis ball and a bowling ball are simultaneously released from rest at the top of your school building. The ball to reach the ground first will be the tennis ball. bowling ball. both will hit at the same time. any of the above, depending on wind conditions. Answer: B) bowling ball. © 2013 Pearson Education, Inc.

A tennis ball and a bowling ball are simultaneously released from rest at the top of your school building. The ball to reach the ground first will be the tennis ball. bowling ball. both will hit at the same time. any of the above, depending on wind conditions. Explanation: Air resistance (not negligible in this case) will act on both when they fall. But the amount of air resistance on the heavy bowling ball will be small compared with the ball's weight. It will therefore better plow through the air and hit first. Answer: B) bowling ball. © 2013 Pearson Education, Inc.

How hard a boxer's punch lands depends on the mass of what's being hit. the physical condition of the boxer. the boxer's attitude. none of the above. Answer: A) the mass of what's being hit. © 2013 Pearson Education, Inc.

How hard a boxer's punch lands depends on the mass of what's being hit. the physical condition of the boxer. the boxer's attitude. none of the above. Explanation: Attitude is said to be everything, and physical condition is important, but not as answers to this question. Answer: A) the mass of what's being hit. © 2013 Pearson Education, Inc.

The force that directly propels a motor scooter along a highway is that provided by the engine. fuel. tires. road. Answer: D) road. © 2013 Pearson Education, Inc.

The force that directly propels a motor scooter along a highway is that provided by the engine. fuel. tires. road. Explanation: The tires push back on the road, and in so doing, the road pushes forward on the tires. It is this force that is directly responsible for the scooter's motion. Cheers for Newton's third law! Answer: D) road. © 2013 Pearson Education, Inc.

When you jump vertically upward, strictly speaking, you cause Earth to move downward. also move upward with you. remain stationary. move sideways a bit. Answer: A) move downward. © 2013 Pearson Education, Inc.

When you jump vertically upward, strictly speaking, you cause Earth to move downward. also move upward with you. remain stationary. move sideways a bit. Explanation: When you jump upward, you push downward on Earth. Strictly speaking, it therefore moves downward. By how much? Not much, in fact negligibly, because its mass is so much greater than yours. Answer: A) move downward. © 2013 Pearson Education, Inc.

The force that propels a rocket is provided by gravity. its exhaust gases. Newton's laws of motion. the atmosphere against which the rocket pushes. Answer: B) its exhaust gases. © 2013 Pearson Education, Inc.

The force that propels a rocket is provided by gravity. its exhaust gases. Newton's laws of motion. the atmosphere against which the rocket pushes. Explanation: Newton's laws are at play in rocket propulsion, but the actual force propelling the rocket is its exhaust gases. As Newton's third law tells us, if the rocket pushes exhaust gases downward, the gases push the rocket upward. Answer: B) its exhaust gases. © 2013 Pearson Education, Inc.

Anthony is late for class and is soon reprimanded Anthony is late for class and is soon reprimanded. Causes lead to consequences. We can show, however, that this is not an example of Newton's third law because action and supposed reaction are not simultaneous. the laws of physics apply to inanimate situations, not real-life ones. both of the above are true. neither of the above is true. Answer: A) action and supposed reaction are not simultaneous. © 2013 Pearson Education, Inc.

Anthony is late for class and is soon reprimanded Anthony is late for class and is soon reprimanded. Causes lead to consequences. We can show, however, that this is not an example of Newton's third law because action and supposed reaction are not simultaneous. the laws of physics apply to inanimate situations, not real-life ones. both of the above are true. neither of the above is true. Explanation: Answer B is erroneous, for Newton's laws govern both inanimate and animate things. An action–reaction pairing is by definition simultaneous. Answer: A) action and supposed reaction are not simultaneous. © 2013 Pearson Education, Inc.

Consider a pair of force vectors: one 50 N and the other 30 N Consider a pair of force vectors: one 50 N and the other 30 N. These vectors can be combined to produce a resultant of 0 N. 85 N. 90 N. none of the above. Answer: D) none of the above. © 2013 Pearson Education, Inc.

Consider a pair of force vectors: one 50 N and the other 30 N Consider a pair of force vectors: one 50 N and the other 30 N. These vectors can be combined to produce a resultant of 0 N. 85 N. 90 N. none of the above. Answer: D) none of the above. © 2013 Pearson Education, Inc.

Consider a 50-N vector that has a horizontal component of 40 N Consider a 50-N vector that has a horizontal component of 40 N. The vertical component is then also 40 N. actually 50 N. 90 N. 30 N. Answer: D) 30 N. © 2013 Pearson Education, Inc.

Consider a 50-N vector that has a horizontal component of 40 N Consider a 50-N vector that has a horizontal component of 40 N. The vertical component is then also 40 N. actually 50 N. 90 N. 30 N. Answer: D) 30 N. © 2013 Pearson Education, Inc.

A 10-N vector and a 5-N vector can produce resultants of 5 N or 15 N when they are at a slight angle to each other. perpendicular to each other. parallel to each other. none of the above. Answer: C) parallel to each other. © 2013 Pearson Education, Inc.

A 10-N vector and a 5-N vector can produce resultants of 5 N or 15 N when they are at a slight angle to each other. perpendicular to each other. parallel to each other. none of the above. Answer: C) parallel to each other. © 2013 Pearson Education, Inc.

The laws of physics that were employed to get humans to the Moon are Newton's laws of motion. special relativity. general relativity. all of the above. Answer: A) Newton's laws of motion. © 2013 Pearson Education, Inc.

The laws of physics that were employed to get humans to the Moon are Newton's laws of motion. special relativity. general relativity. all of the above. Explanation: As the concluding paragraph of Chapter 3 states, Newton's laws were and are sufficient for getting humans to the Moon! Answer: A) Newton's laws of motion. © 2013 Pearson Education, Inc.