Conceptual Physical Science 5e – Chapter 1 © 2012 Pearson Education, Inc. Conceptual Physical Science 5 th Edition Chapter 1: Patterns of Motion and Equilibrium

Conceptual Physical Science 5e – Chapter 1

© 2012 Pearson Education, Inc.

Conceptual PhysicalScience

5th Edition

Chapter 1:

Patterns of Motion and Equilibrium




The force due to gravity on a body is the body’s

A. mass.

B. weight.

C. density.

D. All of the above.



The force due to gravity on a body is the body’s

A. mass.

B. weight.

C. density.




When the mass of an object is compared to its volume, the concept is

A. mass.

B. weight.

C. volume.

D. density.



When the mass of an object is compared to its volume, the concept is

A. mass.

B. weight.

C. volume.

D. density.



When we say that 1 kilogram weighs 10 N, we mean that

A. 1 kg is 10 N.

B. it’s true at Earth’s surface.

C. it’s true everywhere.

D. mass and weight are one and the same.



When we say that 1 kilogram weighs 10 N, we mean that

A. 1 kg is 10 N.

B. it’s true at Earth’s surface.

C. it’s true everywhere.

D. mass and weight are one and the same.



The mass of 1 kilogram of iron

A. is less on the Moon.

B. is the same on the Moon.

C. is greater on the Moon.

D. weighs the same everywhere.



The mass of 1 kilogram of iron

A. is less on the Moon.

B. is the same on the Moon.

C. is greater on the Moon.

D. weighs the same everywhere.

Comment:

But is the weight of 1 kg of iron the same on the Earth and the Moon?



A pair of 3-N and 4-N forces CANNOT have a resultant of

A. 0 N.

B. 1 N.

C. 7 N.

D. But it can have any of the above.



A pair of 3-N and 4-N forces CANNOT have a resultant of

A. 0 N.

B. 1 N.

C. 7 N.

D. But it can have any of the above.

Explanation:

When parallel, the two vectors can add to 7 N or subtract to 1 N. They cannot cancel to zero.



A pair of parallel forces of 8 N and 12 N can have a resultant of

A. 4 N.

B. 20 N.

C. Both of the above.

D. Neither of the above.



A pair of parallel forces of 8 N and 12 N can have a resultant of

A. 4 N.

B. 20 N.



Explanation:

When parallel, 12 N + 8 N = 20 N, or 12 N – 8 N = 4 N.



The equilibrium rule, F = 0, applies to

A. objects or systems at rest.

B. objects or systems in uniform motion in a straight line.


D. None of the above.



The equilibrium rule, F = 0, applies to

A. objects or systems at rest.

B. objects or systems in uniform motion in a straight line.



Comment:

We say objects moving with uniform motion in a straight line are not accelerating.



When you stand on two bathroom scales, with more weight on one scale than on the other, the readings on both scales will

A. cancel to zero.

B. add to equal your weight.

C. add to be somewhat less than your weight.

D. add to be somewhat more than your weight.



When you stand on two bathroom scales, with more weight on one scale than on the other, the readings on both scales will

A. cancel to zero.

B. add to equal your weight.

C. add to be somewhat less than your weight.

D. add to be somewhat more than your weight.



When Nellie Newton hangs by a pair of vertical ropes, the tension in each rope will be

A. less than half her weight.

B. half her weight.

C. more than half her weight.

D. equal to her weight.



When Nellie Newton hangs by a pair of vertical ropes, the tension in each rope will be

A. less than half her weight.

B. half her weight.

C. more than half her weight.

D. equal to her weight.



When an airplane flies horizontally at constant speed in a straight line, the air drag on the plane is

A. less than the amount of thrust.

B. equal to the amount of thrust.

C. more than the amount of thrust.




When an airplane flies horizontally at constant speed in a straight line, the air drag on the plane is

A. less than the amount of thrust.

B. equal to the amount of thrust.

C. more than the amount of thrust.




When an airplane flying horizontally in a straight line gains speed, the thrust on the plane is

A. less than the amount of air drag.

B. equal to the amount of air drag.

C. more than the amount of air drag.




When an airplane flying horizontally in a straight line gains speed, the thrust on the plane is

A. less than the amount of air drag.

B. equal to the amount of air drag.

C. more than the amount of air drag.


Explanation:

In gaining speed, the net force is greater than zero in the direction of the thrust, so thrust exceeds air drag. It is not in equilibrium.



The force of friction between materials sliding against each other depends on

A. the kind of materials.

B. the roughness of the materials.

C. the force with which they are pressed together.




The force of friction between materials sliding against each other depends on

A. the kind of materials.

B. the roughness of the materials.

C. the force with which they are pressed together.




The difference between speed and velocity mostly involves

A. amount.

B. direction.

C. acceleration.




The difference between speed and velocity mostly involves

A. amount.

B. direction.

C. acceleration.




The kind of speed you read on a speedometer is

A. average speed.

B. instantaneous speed.

C. changing speed.

D. constant speed.



The kind of speed you read on a speedometer is

A. average speed.

B. instantaneous speed.

C. changing speed.

D. constant speed.



Distance traveled is equal to average speed multiplied by

A. distance.

B. time.

C. acceleration.

D. instantaneous speed.



average speed total distance traveled

travel time total distance traveled average speed travel time

Distance traveled is equal to average speed multiplied by

A. distance.

B. time.

C. acceleration.

D. instantaneous speed.

Comment:



Constant speed in a constant direction is

A. constant velocity.

B. acceleration.





Constant speed in a constant direction is

A. constant velocity.

B. acceleration.





A hungry bee looking directly ahead sees a flower in a5-m/s breeze. When it gets to the flower, how fast and in what direction should it fly in order to hover above the flower?

A. The bee should fly 5 m/s into the breeze.B. The bee should fly 5 m/s away from the breeze. C. The bee will not be able to fly in a 5-m/s breeze.D. The bee will not be able to reach the flower.



A hungry bee looking directly ahead sees a flower in a5-m/s breeze. When it gets to the flower, how fast and in what direction should it fly in order to hover above the flower?

A. The bee should fly 5 m/s into the breeze.B. The bee should fly 5 m/s away from the breeze. C. The bee will not be able to fly in a 5-m/s breeze.D. The bee will not be able to reach the flower.

Explanation:When just above the flower, it should fly at 5-m/s into the breeze in order to hover at rest. This is why bees grip onto a flower to prevent from being blown off.



When a car rounds a curve, it is

A. moving uniformly.

B. accelerating.

C. in rotational equilibrium.

D. changing its speed.



When a car rounds a curve, it is

A. moving uniformly.

B. accelerating.

C. in rotational equilibrium.

D. changing its speed.



When a bird flies at 8 km/h in an 8-km/h headwind (moving against the wind), the speed of the bird relative to the ground is

A. zero.

B. 8 km/h.

C. 16 km/h.

D. more than 16 km/h.



When a bird flies at 8 km/h in an 8-km/h headwind (moving against the wind), the speed of the bird relative to the ground is

A. zero.

B. 8 km/h.

C. 16 km/h.

D. more than 16 km/h.

Comment:

And if it turns around and flies with the wind, its ground speed will be 16 km/h.



If a motor vehicle increases its speed by 4 km/h each second, its acceleration is

A. 4 km/h.

B. 4 km/h per second.

C. 4 m/s per second.

D. 4 m/s.



If a motor vehicle increases its speed by 4 km/h each second, its acceleration is

A. 4 km/h.

B. 4 km/h per second.

C. 4 m/s per second.

D. 4 m/s.



When a ball rolling down an inclined plane gains 4 m/s each second, the acceleration of the ball is

A. 0.

B. 4 m/s.

C. 4 m/s2.




When a ball rolling down an inclined plane gains 4 m/s each second, the acceleration of the ball is

A. 0.

B. 4 m/s.

C. 4 m/s2.




A body undergoes acceleration whenever there is a change in its

A. speed.B. velocity. C. direction.D. All of the above.



A body undergoes acceleration whenever there is a change in its

A. speed.B. velocity. C. direction.D. All of the above.

Explanation:The figure says it all!



A ball initially at rest rolls along a pair of equal-length tracks A and B. It will roll faster when

A. in the dip of track B.

B. at the end of track B.

C. either in the dip or at the end of track B.

D. at the end of track A.



A ball initially at rest rolls along a pair of equal-length tracks A and B. It will roll faster when

A. in the dip of track B.

B. at the end of track B.

C. either in the dip or at the end of track B.

D. at the end of track A.



A ball rolls along equal-length tracks A and B. Due to increased speed in the dip, it will have an overall greater average speed on track

A. A.

B. B.

C. Both the same.




A ball rolls along equal-length tracks A and B. Due to increased speed in the dip, it will have an overall greater average speed on track

A. A.

B. B.

C. Both the same.




A ball rolls along equal-length tracks A and B. It will reach the end of track B

A. sooner than along track A.B. at the same time as along track A. C. later than along track A.D. None of these make sense.



A ball rolls along equal-length tracks A and B. It will reach the end of track B

A. sooner than along track A.B. at the same time as along track A. C. later than along track A.D. None of these make sense.

Comment:So Ball B wins the race, but at the same final speed!



If you drop a boulder from a tall cliff, as it falls it will gain

A. 10 m/s of speed each second.

B. more and more speed each second.

C. equal amount of falling distance each second.




If you drop a boulder from a tall cliff, as it falls it will gain

A. 10 m/s of speed each second.

B. more and more speed each second.

C. equal amount of falling distance each second.


Comment:

Answer B is incorrect, for a boulder in free fall gains the same amount of speed each second.



A. the same.

B. 10 m/s.

C. 20 m/s.

D. 40 m/s.

Explanation:

A free-falling object changes its speed by 10 m/s each second. 30 m/s – 10 m/s = 20 m/s. If it were moving upward, technically still in “free fall,” its speed 1 second earlier would be 40 m/s.

After being dropped from the top of a high building, a free-falling object has a speed of 30 m/s at one instant. Exactly 1 second earlier, its speed was



After being dropped from the top of a high building, a free-falling object has a speed of 30 m/s at one instant. Exactly 1 second earlier, its speed was

A. the same.

B. 10 m/s.

C. 20 m/s.

D. 40 m/s.

Explanation:

A free-falling object changes its speed by 10 m/s each second.

30 m/s – 10 m/s = 20 m/s. If it were moving upward, technically still in “free fall,” its speed 1 second earlier would be 40 m/s.



Toss a ball straight upward, and each second on the way to the top it

A. loses 10 m/s in speed.

B. accelerates upward.





Toss a ball straight upward, and each second on the way to the top it

A. loses 10 m/s in speed.

B. accelerates upward.





When a ball is tossed straight upward, the direction of its acceleration is

A. upward also.

B. downward, toward Earth’s center.

C. actually horizontal.

D. at some sort of a strange angle.



When a ball is tossed straight upward, the direction of its acceleration is

A. upward also.

B. downward, toward Earth’s center.

C. actually horizontal.

D. at some sort of a strange angle.



The longest that anyone in your school can be in the air when jumping straight upward, landing at the same place, is

A. less than 1 second.

B. about 1 second.

C. about 2 seconds.

D. more than 2 seconds.



The longest that anyone in your school can be in the air when jumping straight upward, landing at the same place, is

A. less than 1 second.

B. about 1 second.

C. about 2 seconds.

D. more than 2 seconds.

Comment:

Even basketball legend Michael Jordan had a hang time of less than 1 second.

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Conceptual Physical Science 5e – Chapter 1 © 2012 Pearson Education, Inc. Conceptual Physical Science 5 th Edition Chapter 1: Patterns of Motion and Equilibrium