Physics: Chapter 2 Test

1. What is the length of the object pictured next to the metric ruler?

2.60 inches

2.60 centimeters

2.5 centimeters

3.5 centimeters

The object pictured next to the metric ruler has a length of 2.60 centimeters.

Explanation

The object pictured next to the metric ruler has a length of 2.60 centimeters.

2. The unit of time most often used by physicists is the:

Second

Minute

Hour

Year

Physicists commonly use the unit of time known as the second. This is because the second is a standardized and universally accepted unit of time measurement in the field of physics. It is defined as the duration of 9,192,631,770 oscillations of a cesium-133 atom. The second is widely used in various scientific calculations and experiments, making it the preferred unit of time for physicists.

Explanation

Physicists commonly use the unit of time known as the second. This is because the second is a standardized and universally accepted unit of time measurement in the field of physics. It is defined as the duration of 9,192,631,770 oscillations of a cesium-133 atom. The second is widely used in various scientific calculations and experiments, making it the preferred unit of time for physicists.

3. Using scientific notation, the number 0.00000125 is written as:

1/800,000

1.25 x 10^-6

1.25 x 10^6

8.00 x 10^5

The number 0.00000125 can be expressed in scientific notation as 1.25 x 10^-6. In scientific notation, the number is written as a decimal between 1 and 10, multiplied by a power of 10. In this case, the decimal is 1.25 and it is multiplied by 10 raised to the power of -6, indicating that the decimal point is moved 6 places to the left.

Explanation

The number 0.00000125 can be expressed in scientific notation as 1.25 x 10^-6. In scientific notation, the number is written as a decimal between 1 and 10, multiplied by a power of 10. In this case, the decimal is 1.25 and it is multiplied by 10 raised to the power of -6, indicating that the decimal point is moved 6 places to the left.

4. Your normal stride as you walk or run would most closely approximate a:

Millimeter

Centimeter

Meter

Kilometer

The normal stride while walking or running is a distance that is neither too short nor too long. It is a comfortable distance that allows for efficient movement. A meter is a unit of length that is commonly used to measure everyday distances, making it the most appropriate option for approximating the normal stride. A millimeter is too small a unit, a centimeter is slightly short, and a kilometer is too long to represent the typical stride length.

Explanation

The normal stride while walking or running is a distance that is neither too short nor too long. It is a comfortable distance that allows for efficient movement. A meter is a unit of length that is commonly used to measure everyday distances, making it the most appropriate option for approximating the normal stride. A millimeter is too small a unit, a centimeter is slightly short, and a kilometer is too long to represent the typical stride length.

5. The conversion factor for changing one unit of length to another in the metric system is a multiple of:

3

10

12

5280

In the metric system, the conversion factor for changing one unit of length to another is always a multiple of 10. This is because the metric system is based on powers of 10, making it a decimal-based system. The prefixes used in the metric system, such as kilo-, centi-, and milli-, are all based on multiples or fractions of 10. Therefore, when converting between units of length, you simply need to move the decimal point to the left or right by powers of 10 to obtain the desired unit.

Explanation

In the metric system, the conversion factor for changing one unit of length to another is always a multiple of 10. This is because the metric system is based on powers of 10, making it a decimal-based system. The prefixes used in the metric system, such as kilo-, centi-, and milli-, are all based on multiples or fractions of 10. Therefore, when converting between units of length, you simply need to move the decimal point to the left or right by powers of 10 to obtain the desired unit.

6. If scientific notation were used to represent the number 5,280, it would be written:

5:2:8:0\x00

5.280 × 10^3

52.80 x 10^2

5,280 x 10^0

The correct answer is 5.280 × 10^3. This is because scientific notation is used to represent very large or very small numbers in a compact and standardized format. In scientific notation, the number is written as a decimal number between 1 and 10, multiplied by a power of 10. In this case, 5,280 is written as 5.280 and multiplied by 10^3, which means moving the decimal point 3 places to the right.

Explanation

The correct answer is 5.280 × 10^3. This is because scientific notation is used to represent very large or very small numbers in a compact and standardized format. In scientific notation, the number is written as a decimal number between 1 and 10, multiplied by a power of 10. In this case, 5,280 is written as 5.280 and multiplied by 10^3, which means moving the decimal point 3 places to the right.

7. The approximate number of days in one year is 365.25. The number of seconds in one year is:

21,915

1,314,900

31,558,000

3,144,800,000

The approximate number of days in one year is 365.25. To find the number of seconds in one year, we need to multiply the number of days by the number of seconds in a day. There are 24 hours in a day, 60 minutes in an hour, and 60 seconds in a minute, so there are 24 x 60 x 60 = 86,400 seconds in a day. Multiplying this by 365.25 gives us 31,558,000 seconds in one year.

Explanation

The approximate number of days in one year is 365.25. To find the number of seconds in one year, we need to multiply the number of days by the number of seconds in a day. There are 24 hours in a day, 60 minutes in an hour, and 60 seconds in a minute, so there are 24 x 60 x 60 = 86,400 seconds in a day. Multiplying this by 365.25 gives us 31,558,000 seconds in one year.

8. The metric unit of length closest to the thickness of a toothpick is the:

Kilometer

Meter

Centimeter

Millimeter

The metric unit of length closest to the thickness of a toothpick is the millimeter. A toothpick is very thin, and a millimeter is a unit of measurement that is smaller than a centimeter or a meter. A millimeter is commonly used to measure small objects or distances, making it the most appropriate unit for measuring the thickness of a toothpick.

Explanation

The metric unit of length closest to the thickness of a toothpick is the millimeter. A toothpick is very thin, and a millimeter is a unit of measurement that is smaller than a centimeter or a meter. A millimeter is commonly used to measure small objects or distances, making it the most appropriate unit for measuring the thickness of a toothpick.

9. The conversion factor for changing one unit of length to another in the English system may be:

3

12

5280

All of the above

The correct answer is "All of the above" because the English system of measurement includes multiple conversion factors for changing units of length. The conversion factor of 3 is used to convert feet to yards, 12 is used to convert inches to feet, and 5280 is used to convert feet to miles. Therefore, all three conversion factors are valid in the English system.

Explanation

The correct answer is "All of the above" because the English system of measurement includes multiple conversion factors for changing units of length. The conversion factor of 3 is used to convert feet to yards, 12 is used to convert inches to feet, and 5280 is used to convert feet to miles. Therefore, all three conversion factors are valid in the English system.

10. One kilogram of mass has a weight of about 2.2 pounds. The weight of a 50.0-kilogram Rottweiller expressed in pounds is:

11.0

110

2.27

22.7

The correct answer is 110 because to convert kilograms to pounds, you multiply the mass in kilograms by the conversion factor of 2.2. Therefore, 50 kilograms multiplied by 2.2 equals 110 pounds.

Explanation

The correct answer is 110 because to convert kilograms to pounds, you multiply the mass in kilograms by the conversion factor of 2.2. Therefore, 50 kilograms multiplied by 2.2 equals 110 pounds.

11. An electronic clock gives the elapsed time as 7:34:21. How many seconds does this represent?

73,421

27,261

2,481

734.21

The electronic clock displays the elapsed time as 7 hours, 34 minutes, and 21 seconds. To calculate the total number of seconds, we convert the hours and minutes to seconds and add them to the given seconds. There are 7 hours x 60 minutes/hour x 60 seconds/minute = 25,200 seconds in 7 hours. There are 34 minutes x 60 seconds/minute = 2,040 seconds in 34 minutes. Adding these together with the given 21 seconds gives a total of 27,261 seconds.

Explanation

The electronic clock displays the elapsed time as 7 hours, 34 minutes, and 21 seconds. To calculate the total number of seconds, we convert the hours and minutes to seconds and add them to the given seconds. There are 7 hours x 60 minutes/hour x 60 seconds/minute = 25,200 seconds in 7 hours. There are 34 minutes x 60 seconds/minute = 2,040 seconds in 34 minutes. Adding these together with the given 21 seconds gives a total of 27,261 seconds.

12. The kilogram, the unit used as the standard for mass, is equal to the mass of:

1,000 cubic centimeters of water

1 cubic centimeter of water

A 1,000-cubic centimeter platinum-iridium cylinder in France

A 1-cubic centimeter platinum-iridium cylinder in France

The kilogram is defined as the mass of 1,000 cubic centimeters of water. This means that if you were to measure the mass of 1,000 cubic centimeters of water, it would be equal to one kilogram. This definition was established as a way to have a consistent and reproducible standard for mass. By using water as the reference, it allows for easy comparison and calibration of measuring instruments.

Explanation

The kilogram is defined as the mass of 1,000 cubic centimeters of water. This means that if you were to measure the mass of 1,000 cubic centimeters of water, it would be equal to one kilogram. This definition was established as a way to have a consistent and reproducible standard for mass. By using water as the reference, it allows for easy comparison and calibration of measuring instruments.

13. The measure of mass when it is thought of as a resistance to change in motion is called:

Velocity

Acceleration

Inertia

Speed

Inertia is the correct answer because it refers to the measure of mass as a resistance to change in motion. Inertia is the property of an object that causes it to resist any change in its state of motion. It is directly related to an object's mass, with more massive objects having greater inertia.

Explanation

Inertia is the correct answer because it refers to the measure of mass as a resistance to change in motion. Inertia is the property of an object that causes it to resist any change in its state of motion. It is directly related to an object's mass, with more massive objects having greater inertia.

14. Using scientific notation, the ratio 3.2 is written as: ----------- 1,280

0.0025

25 x 10^4

2.5 x 10^-3

4.00 x 10^2

The given ratio 3.2 can be written in scientific notation as 2.5 x 10^-3. This is because when converting a number to scientific notation, we express it as a number between 1 and 10 multiplied by a power of 10. In this case, 3.2 can be written as 2.5 (which is between 1 and 10) multiplied by 10^-3 (which is the power of 10 needed to make the number 3.2).

Explanation

The given ratio 3.2 can be written in scientific notation as 2.5 x 10^-3. This is because when converting a number to scientific notation, we express it as a number between 1 and 10 multiplied by a power of 10. In this case, 3.2 can be written as 2.5 (which is between 1 and 10) multiplied by 10^-3 (which is the power of 10 needed to make the number 3.2).

15. The weight of a BMW Z-3 1.9 roadster is approximately 2,350 pounds. The weight expressed in scientific notation is:

2.35 x 10^3 pounds

23.50 x 10^3 pounds

2.35 x 10^2 pounds

23.5 x 10^2 pounds

The weight of the BMW Z-3 1.9 roadster is approximately 2,350 pounds. This can be expressed in scientific notation as 2.35 x 10^3 pounds. In scientific notation, the number is written as a decimal between 1 and 10, multiplied by a power of 10. In this case, the decimal is 2.35, and it is multiplied by 10^3, which means the decimal point is moved three places to the right. This notation is used to represent very large or very small numbers in a concise and standardized format.

Explanation

The weight of the BMW Z-3 1.9 roadster is approximately 2,350 pounds. This can be expressed in scientific notation as 2.35 x 10^3 pounds. In scientific notation, the number is written as a decimal between 1 and 10, multiplied by a power of 10. In this case, the decimal is 2.35, and it is multiplied by 10^3, which means the decimal point is moved three places to the right. This notation is used to represent very large or very small numbers in a concise and standardized format.

16. Compared to a bicycle, an automobile pushed by a student has more:

Speed

Velocity

Acceleration

Inertia

Inertia is the tendency of an object to resist changes in its motion. In this scenario, compared to a bicycle, an automobile pushed by a student would have more inertia because it has more mass. The greater the mass of an object, the greater its inertia. Therefore, the automobile would be more difficult to accelerate or decelerate compared to a bicycle, as it would require more force to overcome its greater inertia.

Explanation

Inertia is the tendency of an object to resist changes in its motion. In this scenario, compared to a bicycle, an automobile pushed by a student would have more inertia because it has more mass. The greater the mass of an object, the greater its inertia. Therefore, the automobile would be more difficult to accelerate or decelerate compared to a bicycle, as it would require more force to overcome its greater inertia.

17. The smallest measurable length of a centimeter stick is 0.001 cm. Which of the following best describes this limit?

Accuracy

Precision

Rounding

Experiment

Precision refers to the level of detail or exactness in a measurement. In this case, the smallest measurable length of 0.001 cm indicates a high level of precision because it allows for very small increments to be measured. Accuracy, on the other hand, refers to how close a measurement is to the true value, which is not mentioned in the question. Rounding and experiment are not relevant to describing the limit of the smallest measurable length.

Explanation

Precision refers to the level of detail or exactness in a measurement. In this case, the smallest measurable length of 0.001 cm indicates a high level of precision because it allows for very small increments to be measured. Accuracy, on the other hand, refers to how close a measurement is to the true value, which is not mentioned in the question. Rounding and experiment are not relevant to describing the limit of the smallest measurable length.

18. Compared to a 1.0-kilogram chunk of iron, a 1.0-kilogram piece of Styrofoam:

Has a larger mass

Contains more matter

Takes up more space

Has more inertia

Styrofoam is less dense than iron, so even though both have the same mass of 1.0 kilogram, the Styrofoam takes up more space. This is because the particles in Styrofoam are more spread out, resulting in a larger volume compared to the iron. Therefore, the Styrofoam occupies a larger physical space even though it has the same mass.

Explanation

Styrofoam is less dense than iron, so even though both have the same mass of 1.0 kilogram, the Styrofoam takes up more space. This is because the particles in Styrofoam are more spread out, resulting in a larger volume compared to the iron. Therefore, the Styrofoam occupies a larger physical space even though it has the same mass.

19. The value for the ratio of the mass of 1 kilogram to the mass of 1 proton is about:

1.8 x 10^3

5.6 x 10^-4

5.9 x 10^26

5.9 x 10^-26

The given answer, 5.9 x 10^26, represents the ratio of the mass of 1 kilogram to the mass of 1 proton. This means that 1 kilogram is approximately 5.9 x 10^26 times heavier than 1 proton.

Explanation

The given answer, 5.9 x 10^26, represents the ratio of the mass of 1 kilogram to the mass of 1 proton. This means that 1 kilogram is approximately 5.9 x 10^26 times heavier than 1 proton.

20. The standard second is determined by comparison with the:

Average solar day

Speed of light at the equator

Standard pendulum in France

Oscillations of a cesium-133 atom

The standard second is determined by the oscillations of a cesium-133 atom. Cesium-133 atoms have a very stable frequency of oscillation, which makes them ideal for measuring time accurately. By defining the second based on the oscillations of cesium-133 atoms, we can ensure that time measurements are consistent and precise. This method of timekeeping is used in atomic clocks, which are the most accurate timekeeping devices available today.

Explanation

The standard second is determined by the oscillations of a cesium-133 atom. Cesium-133 atoms have a very stable frequency of oscillation, which makes them ideal for measuring time accurately. By defining the second based on the oscillations of cesium-133 atoms, we can ensure that time measurements are consistent and precise. This method of timekeeping is used in atomic clocks, which are the most accurate timekeeping devices available today.