Question 1

Since 1967 the standard definition for the second has been based on which of the following?
A)characteristic frequency of the cesium-133 atom
B)average solar day
C)sidereal day
D)Greenwich Civil Time

Accepted Answer

Since 1967, the second has been defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium-133 atom.

Question 2

Since 1983 the standard meter has been defined in terms of which of the following?
A)specific alloy bar housed at Sevres,France
B)wavelength of light emitted by krypton-86
C)distance from the Earth's equator to the North Pole
D)the distance light travels in a certain fraction of a second

Accepted Answer

The standard meter has been defined in terms of the distance that light travels in a certain fraction of a second since 1983. This fraction is 1/299,792,458 of a second. This is known as the speed of light in a vacuum and is a constant value.

Question 3

The speed of a boat is often given in knots.If a speed of 5 knots were expressed in the SI system of units,the units would be:
A)m.
B)s.
C)m/s.
D)kg/s.

Accepted Answer

Knot is a unit of speed equal to one nautical mile per hour, which is approximately equal to 1.852 kilometers per hour. To convert it to SI units, we need to express it in meters per second (m/s), which is commonly used in the International System of Units (SI). Therefore, the correct answer is C) m/s.

Question 4

If the displacement of an object,x,is related to velocity,v,according to the relation x = Av,the constant,A,has the dimension of which of the following?
A)acceleration
B)length
C)time
D)area

Accepted Answer

The dimension of velocity (v) is length/time, and since displacement (x) has the dimension of length, the constant A must have the dimension of time to balance the equation dimensionally.

Question 5

Areas always have dimensions ____ while volumes always have dimensions ____. A)m²,m³ B)L²,L³ C)Both a and b are correct. D)No answer is correct because of the "always."

Accepted Answer

The answer of Areas always have dimensions ____ while volumes...

Question 6

When was the existence of the neutron confirmed?
A)in ancient times
B)in 1895
C)in 1932
D)in 1969

Accepted Answer

The existence of the neutron was confirmed in 1932 by James Chadwick through his experiments which showed that radiation produced by beryllium when bombarded with alpha particles consisted of uncharged particles with a mass similar to that of the proton.

Question 7

If a is acceleration,v is velocity,x is position,and t is time,then which equation is not dimensionally correct? A)t = x/v B)a = v²/x C)v = a/t D)t² = 2x/a

Accepted Answer

The answer of If a is acceleration,v is velocity,x is...

Question 8

Which formula is dimensionally consistent with an expression yielding a value for velocity? (a is acceleration,x is distance,and t is time) A)v/t² B)vx² C)v²/t D)at

Accepted Answer

Velocity has the dimension of distance divided by time. Acceleration (a) has the dimension of distance divided by time squared, and when multiplied by time (t), it gives the dimension of distance divided by time, which is consistent with the dimension of velocity.

Question 9

Which one of the choices below represents the preferred practice regarding significant figures when multiplying the following: 10.5 x 8.8 x 3.14?
A)290
B)290.136
C)290.1
D)300

Accepted Answer

When multiplying, the result should have the same number of significant figures as the factor with the fewest significant figures. Here, 8.8 has two significant figures, so the result should be rounded to two significant figures, which is 290.

Question 10

Which expression is dimensionally consistent with an expression that would yield a value for time^-1? (v is velocity,x is distance,and t is time) A)v/x B)v²/x C)x/t D)v²t

Accepted Answer

A dimensionally consistent expression for time can be derived from the formula $v = \frac{x}{t}$, where $v$ is velocity, $x$ is distance, and $t$ is time. Rearranging for $t$ gives $t = \frac{x}{v}$, which is dimensionally consistent with choice A, $v/x$, when considering the units involved.

Question 11

The nuclei of atoms contain
A)electrons only.
B)neutrons only.
C)protons and electrons.
D)protons and neutrons.

Accepted Answer

The nuclei of atoms contain protons and neutrons. Electrons are found outside the nucleus in the electron cloud.

Question 12

The ratio M/m of the prefixes M and m has what value? A)10³ B)10⁶ C)10⁹ D)10¹⁸

Accepted Answer

The prefix M stands for mega (10^6) and m stands for milli (10^-3). The ratio M/m is 10^6 / 10^-3 = 10^9.

Question 13

The length and width of a standard sheet of paper is measured,and then the area is found by calculation to be 93.50 in².The number of significant figures in the width measurement must be at least: A)1. B)2. C)3. D)4.

Accepted Answer

The answer of The length and width of a standard...

Question 14

One year is about ____ seconds while one day is exactly ____ seconds. A)3.16 x 10⁷,86 400 B)5.26 x 10⁵,86 400 C)3.16 x 10⁷,8 640 D)1.04 x 10⁶,36 000

Accepted Answer

One year is approximately 31,557,600 seconds. This value is closest to option A, which is 3.16 x 10^7. 
One day is exactly 86,400 seconds, which is present in option A. The other options have incorrect values for both year and day.

Question 15

Which one of the choices below represents the preferred practice regarding significant figures when adding the following: 12.4 + 11 + 67.37 + 4.201?
A)94.971
B)94.97
C)95.0
D)95

Accepted Answer

When adding numbers, the result should be rounded to the least number of decimal places in any of the numbers being added. Here, the number 11 has zero decimal places, so the sum should be rounded to the nearest whole number, which is 95.

Question 16

The prefixes which are abbreviated p,n,and G represent which of the following? A)10^-2,10^-6,and 10¹⁵ B)10^-9,10⁶,and 10¹⁰ C)10^-12,10^-9,and 10⁹ D)10^-15,10^-6,and 10¹²

Accepted Answer

The prefixes p, n, and G represent pico (10^-12), nano (10^-9), and giga (10^9), respectively.

Question 17

The proton contains which of the following combination of quarks?
A)two up quarks and one down quark
B)one up quark and two down quarks
C)one top quark and two bottom quarks
D)two top quarks and one bottom quark

Accepted Answer

The proton is composed of two up quarks and one down quark. This combination gives the proton a positive charge.

Question 18

Suppose an equation relating position,x,to time,t,is given by x = b t³ + c t⁴,where b and c are constants.The dimensions of b and c are respectively: A)T³,T⁴. B)1/T³,1/T⁴. C)L/T³,L/T⁴. D)L²*T³,L²*T⁴.

Accepted Answer

The dimensions of position x are [L]. For the term bt^3 to have dimensions of [L], b must have dimensions of [L/T^3]. Similarly, for the term ct^4 to have dimensions of [L], c must have dimensions of [L/T^4].

Question 19

Calculate (0.82 + 0.042) x (4.4 x 10³), keeping only significant figures. A)3 800 B)3 784 C)3 793 D)3 520

Accepted Answer

The sum (0.82 + 0.042) is 0.862, which has 2 significant figures. The product (4.4 x 10^3) has 2 significant figures. The result should have 2 significant figures: (0.862 x 4.4 x 10^3) = 3792.8, rounded to 2 significant figures is 3800.

Question 20

In mechanics,physicists use three basic quantities to derive additional quantities.Mass is one of the three quantities.What are the other two?
A)length and force
B)power and force
C)length and time
D)force and time

Accepted Answer

The other two basic quantities used in mechanics are length and time. These quantities are used to derive additional quantities such as velocity, acceleration, and displacement. Mass is used in combination with these quantities to derive further quantities such as force and momentum. Therefore, the correct choice is C) length and time.

Quiz 1: Introduction

Since 1967 the standard definition for the second has been based on which of the following?

Since 1983 the standard meter has been defined in terms of which of the following?

The speed of a boat is often given in knots.If a speed of 5 knots were expressed in the SI system of units,the units would be:

If the displacement of an object,x,is related to velocity,v,according to the relation x = Av,the constant,A,has the dimension of which of the following?

Areas always have dimensions while volumes always have dimensions .

When was the existence of the neutron confirmed?

If a is acceleration,v is velocity,x is position,and t is time,then which equation is not dimensionally correct?

Which formula is dimensionally consistent with an expression yielding a value for velocity? (a is acceleration,x is distance,and t is time)

Which one of the choices below represents the preferred practice regarding significant figures when multiplying the following: 10.5 x 8.8 x 3.14?

Which expression is dimensionally consistent with an expression that would yield a value for time^-1? (v is velocity,x is distance,and t is time)

The nuclei of atoms contain

The ratio M/m of the prefixes M and m has what value?

The length and width of a standard sheet of paper is measured,and then the area is found by calculation to be 93.50 in².The number of significant figures in the width measurement must be at least:

One year is about seconds while one day is exactly seconds.

Which one of the choices below represents the preferred practice regarding significant figures when adding the following: 12.4 + 11 + 67.37 + 4.201?

The prefixes which are abbreviated p,n,and G represent which of the following?

The proton contains which of the following combination of quarks?

Suppose an equation relating position,x,to time,t,is given by x = b t³ + c t⁴,where b and c are constants.The dimensions of b and c are respectively:

Calculate (0.82 + 0.042) x (4.4 x 10³) , keeping only significant figures.

In mechanics,physicists use three basic quantities to derive additional quantities.Mass is one of the three quantities.What are the other two?