Physics Test 1

Which of the following statements related to vectors is not correct?

a. A "one way" road sign is an example of a vector.

Which of the following uses a derived SI unit measurement? a. time b. speed c. distance d. mass

b. speed

One inch (in) is equal to 2.54 centimeters (cm). How many centimeters are in 12.0 inches?

30.5 cm

Suppose you have $100 that you need to convert to Danish kroner. The conversion rate that day is 5.732 Danish kroner for one American dollar. The business that converts your money charges you a flat fee of 50 Danish kroner for the transaction. Use your knowledge of significant figures to decide which of the following shows the correct amount of Danish kroner that you should receive.

523.2 Danish kroner

Which of the following statements related to conversion factors is false? a.conversion factor is the ratio of the given unit to the required unit. b. A conversion factor does not necessarily convert to standard SI units. c. The expression 60 min / hour is an example of a conversion factor. d. The value of a conversion factor is essentially 1.

A conversion factor is the ratio of the given unit to the required unit.

How many significant figures are there in a measurement 0.30700 cm?

Five significant figures — every digit except the first 0.

The SI unit for mass is the kilogram. Which of the following statements related to mass is not correct?

The definition of a kilogram is based on the mass of a certain number of carbon atoms.

In physics (and in all science) standard units are used to ensure measurement uniformity. Which of the following fictitious units of measurement could not be considered a standard unit? a. The grimph: a distance unit equal to exactly 4 meters. b. The nicket: a time unit equal to exactly 1/45 of a second. c. The pinkie: a distance unit equal to the exact length of the right pinkie finger on the current U.S. president. d. The brund: a unit equal to the mass of two million hydrogen atoms.

The pinkie: a distance unit equal to the exact length of the right pinkie finger on the current U.S. president.

Which of the following best explains why physicists need to use standard units when making measurements?

To make accurate quantitative observations about the physical properties and behavior of things.

Suppose you are asked to determine the perimeter of a seven-sided irregular figure. You make the following measurements: Side 1 = 3.2 m Side 2 = 4.8 m Side 3 = 2.000 m Side 4 = 8.94 m Side 5 = 11 m Side 6 = 7.566 m Side 7 = 4.0 m How many significant figures should there be in your calculation for the perimeter?

Two significant figures

Which of the following shows a measurement that has precisely two significant figures?

a. 98 m

Which of the following shows a measurement that has precisely two significant figures? Select one: a. 98 m b. 2.01 x 103 m c. 403 s d. 2.050 kg

a. 98 m

Which of the following statements related to vectors is not correct? Select one: a. A "one way" road sign is an example of a vector. b. A vector is a physical description that includes both a number and a direction. c. If someone states, "Joe is traveling at 30 miles per hour, due east, on Dansbury Road." You can describe Joe's velocity as a vector. d. The following information is insufficient to to describe a ship's velocity as a vector: "A ship is traveling north by northeast at a rapid speed."

a. A "one way" road sign is an example of a vector. A "one way" road sign is just a direction. If the sign included a speed, then it could be called a vector.

The vector B→ is a scalar multiple of vector A→. The magnitude of B→ is three times the magnitude of A→. Which of the following vector equations describes the relationship between B→ and A→? Select one: a. A→ =13B→ b. A→=3B→ states that the magnitude of A→ is three times that of B→, or equivalently, the magnitude of B→ is one-third of A→. c. 13A→ = B→ d. A→=∣3A→∣B→

a. A→ =13B→

Vectors A→ ,B→ and C→ are shown in the figure. Which of the following is correct? B↙ ↘A C → Select one: a. C→=A→−B→ b. C→=B→−A→ c. C→=A→+B→ d. C→=∣A→∣+∣B→∣

a. C→=A→−B→

Suppose you are told that 15 quarts (qt) = 14.2 liters (L). What is the conversion factor you would use to convert from quarts to liters? What is the conversion factor you would you use to convert liters to quarts?

a. quarts to liters: 14.2 L / 15 qt liters to quarts: 15 qt / 14.2 L

Suppose you are told that 15 quarts (qt) = 14.2 liters (L). What is the conversion factor you would use to convert from quarts to liters? What is the conversion factor you would you use to convert liters to quarts? a. quarts to liters: 14.2 L / 15 qt liters to quarts: 15 qt / 14.2 L b. quarts to liters:15 qt + 14.2 L liters to quarts: 29.2 qt / L c. quarts to liters: 15 qt / 14.2 L liters to quarts: 1.06 qt / L d. quarts to liters: 15 qt • 14.2 L liters to quarts: 213 qt / L

a. quarts to liters: 14.2 L / 15 qt liters to quarts: 15 qt / 14.2 L

How many significant figures should there be for the product of 29 x 3.530 m? a. two significant figures b. three significant figures c. four significant figures d. five significant figures

a. two significant figures

Which of the following does not correctly describe each given vector in terms of the unit vectors? (Note that each grid line is half of a unit.) Select one: a. A→=1.5î +ĵ b. B→=−4ĵ c. C→=î −2ĵ d. D→=−î −3ĵ

b. B→=−4ĵ

Which of the following statements concerning significant figures is not correct? Select one: a. The use of significant digits allows physicists to convey how well they can measure a quantity. b. Not all of physics is verifiable. c. Physics deals with measurements and therefore significant figures are important. d. Measurements of physical quantities are not always known accurately.

b. Not all of physics is verifiable.

Which of the following does not explain the use of SI units in physics?

b. SI units are more difficult to manipulate than old English system units (such as the foot and the pound).

Which of the following does not explain the use of SI units in physics? Select one: a. SI units have been universally accepted as the standard by the scientific community. b. SI units are more difficult to manipulate than old English system units (such as the foot and the pound). c. Physicists are able to measure complicated quantities using mks units. d. SI units are arbitrarily defined.

b. SI units are more difficult to manipulate than old English system units (such as the foot and the pound).

If a 1/4 pound hamburger weighs 113.4 grams, which of the following is a conversion factor for pounds (lb) to grams (g)? Also, how many grams are in 1.4 pounds?

b. The conversion factor is 113.4 g / (1/4 lb). There are 635.0 grams in 1.4 pounds.

If a 1/4 pound hamburger weighs 113.4 grams, which of the following is a conversion factor for pounds (lb) to grams (g)? Also, how many grams are in 1.4 pounds? Select one: a. The conversion factor is (1/4 lb) / 113.4 g. There are 113.4 grams in 1.4 pounds. b. The conversion factor is 113.4 g / (1/4 lb). There are 635.0 grams in 1.4 pounds. c. The conversion factor is (1/4) / 113.4 g. There are 635.0 grams in 1.4 pounds. d. The conversion factor is 113.4 g / (1/4 lb). There are 453.6 grams in 1.4 pounds.

b. The conversion factor is 113.4 g / (1/4 lb). There are 635.0 grams in 1.4 pounds.

The SI unit for mass is the kilogram. Which of the following statements related to mass is not correct? a. The equation 1 kg = 2.2 lb is an example of an SI / non-SI conversion. b. The definition of a kilogram is based on the mass of a certain number of carbon atoms. c. A spring scale measures weight, not mass. d. A kilogram is one of the mks base units.

b. The definition of a kilogram is based on the mass of a certain number of carbon atoms.

Which of the following best defines a second as an SI unit of time?

b. the amount of time that a cesium atom needs to vibrate a specific number of times

Given that A→=Axî +Ayĵ , which of the following is incorrect ? Select one: a. 3A→=3Axî +3Ayĵ b. −2A→=2Axî −2Ayĵ c. −A→=−Axî −Ayĵ d. kA→=kAxî +kAyĵ

b. −2A→=2Axî −2Ayĵ

Suppose you are told that 1 qt = 0.946 L. Which of the following statements is not correct? Select one: a. 1qt/0.964 L = 1 b. 0.964 L/1qt = 1 c. (1 qt/0.946 L)(365) = 365 qt/L d. To convert 3.5 quarts to liters, you would multiply 3.5 quarts by (0.946 L / 1 qt).

c. (1 qt/0.946 L)(365) = 365 qt/L

Suppose a laboratory experiment lasted 4,532 seconds. Which of the following conversion factors would be used to figure out how many hours the experiment lasted? Select one: a. 60 s / 1 min b. 60 min / 1 hr c. Both 60 s / 1 min and 60 min / 1 hr d. Both 60 s / 1 min and 60 min / 1 hr, and 24 hr / 1 day

c. Both 60 s / 1 min and 60 min / 1 hr You need to convert from seconds to minutes and from minutes to hours.

Which of the following statements about SI units is NOT correct? a. The prefix centi - denotes 1/100 of a unit. b. 1 milligram < 1 centigram < 1 gram < 1 kilogram c. The cgs system is not considered a standard SI system. d. The prefix kilo- denotes 1,000 units.

c. The cgs system is not considered a standard SI system.

A→=−12B→ Which of the following is incorrect? Select one: a. 2A→=−B→ b. The magnitude of A→ is half that of B→. c. The directions of A→ and B→ are the same. d. A→+12B→=0

c. The directions of A→ and B→ are the same.

Suppose that an environmental study determines that a town produces approximately 2,000 lb of trash each day. The study group decides to convert their findings to SI units, using the conversion 1 lb = 0.4536 kg. They report that the town produces 907.2 kg of trash each day. Which of the following is correct? a. The study group used the wrong conversion factor. They should have reported that the town produces 4,409 kg of trash each day. b. The study group used the correct conversion, but they should have reported that the town produces 907 kg of trash each day. c. The study group used the correct conversion factor but did not account for significant digits. d. None of these statements are correct.

c. The study group used the correct conversion factor but did not account for significant digits.

Suppose that an environmental study determines that a town produces approximately 2,000 lb of trash each day. The study group decides to convert their findings to SI units, using the conversion 1 lb = 0.4536 kg. They report that the town produces 907.2 kg of trash each day. Which of the following is correct? Select one: a. The study group used the wrong conversion factor. They should have reported that the town produces 4,409 kg of trash each day. b. The study group used the correct conversion, but they should have reported that the town produces 907 kg of trash each day. c. The study group used the correct conversion factor but did not account for significant digits. d. None of these statements are correct.

c. The study group used the correct conversion factor but did not account for significant digits. The study group incorrectly assumed that 2,000 lb has four significant figures, instead of one significant digit. Therefore, the converted number should have just one significant figure, not four.

Which of the following quantities is not a vector? Select one: a. velocity(example: 2.0 m / s south) b. force(example: 15 Newtons downward) c. speed(example: 70 miles per hour) d. displacement(example: 20 meters northeast of the lighthouse)

c. speed (example: 70 miles per hour) Speed is not a vector because it has only magnitude. There is no direction associated with speed.

Suppose you are told that the mass of an object is 1.283 kg. What is the implied range for the mass of this object? Select one: a. 1.2kg→1.3kg b. 1kg→2kg c. 1.283kg→1.284kg d. 1.282kg→1.284kg

d. 1.282kg --> 1.284 kg The range is defined by 3-1 and 3+1 in the thousandths place.

Which of the following quantities describes a vector?

d. All of the above

Given two vectors A→ and B→, which of the following is the correct method for adding A→ and B→? A↗↑B Select one: a. Move A→ parallel to itself placing the tail of A→ at the tail of B→, and then draw a vector from the tip of B→ to the tail of A→. b. Move B→ parallel to itself placing the tail of B→ at the tip of A→, and then draw a vector from the tail of A→ to the tip of B→. c. Move A→ parallel to itself placing the tail of A→ at the tip of B→, and then draw a vector from the tail of B→ to the tip of A→. d. Answers A and B

d. Answers A and B The methods described in Answers A and B describe the geometrical method for finding the sum of two vectors.

The circumference of a circle is defined by the equation C=2piR, where pi=3.14. Suppose that r=0.0347 m. Which of the following correctly shows the circumference of the circle? a. C = 0.378 m^2 b. C = 0.237916 m c. C = 0.2 m d. C = 0.218 m

d. C = 0.218 m

Which of the following statements about SI distance units is not correct? a. Both a meter and a kilometer are SI units. b. A mile is not an SI unit. c. A meter currently has a universal unit definition. d. Converting a meter to feet is an example of a conversion involving two different SI units for distance.

d. Converting a meter to feet is an example of a conversion involving two different SI units for distance.

Which of the following statements about SI distance units is not correct? Select one: a. Both a meter and a kilometer are SI units. b. A mile is not an SI unit. c. A meter currently has a universal unit definition. d. Converting a meter to feet is an example of a conversion involving two different SI units for distance.

d. Converting a meter to feet is an example of a conversion involving two different SI units for distance.

Which of the following statements about SI distance units is not correct? a. Both a meter and a kilometer are SI units. b. A mile is not an SI unit. c. A meter currently has a universal unit definition. d. Converting a meter to feet is an example of a conversion involving two different SI units for distance.

d. Converting a meter to feet is an example of a conversion involving two different SI units for distance.

Which of the following statements about SI distance units is notcorrect?

d. Converting a meter to feet is an example of a conversion involving two different SI units for distance.

What are SI units? a. Standard Index units of measurement b. Units from the old English measurement system c. International time units d. Systeme International units of measurement

d. Systeme Internacionale units of measurement

The work W done by a system that expands against an external pressure is W = -P x change in V, where change in V is V final - V initial Suppose the initial volume of a gas is 198 L, the work done by the gas is -2.0 x 10^4 J and the pressure s 1.0 atm. Which of the following is needed to find the final volume of the gas? a. a conversion from L to J b. a conversion from J to L c. a conversion from J / L to atm d. a conversion from J / atm to L

d. a conversion from J / atm to L

Which of the following explains how to describe a vector? Select one: a. using magnitude and direction b. using an x- and y-coordinate system c. using unit vectors d. all of the above

d. all of the above

In order to understand vectors, you must understand some basic trigonometry. Which of the following correctly relates x, y, t and θ? y (x,y) ↑ ╱│ ↑ t ╱ │ y ↑ ╱ │ ↑╱ ) θ │ ↑⟼⟶⟶⟶⟶⟶ x x Select one: a. x= t sinθ; y= t cosθ; tanθ= y/x; t= √(x2+y2) b. x= cosθ; y= sinθ; tanθ=y/x; t= √(x2+y2) c. x= t cosθ; y= t sinθ; tanθ=y/x; t= √(x2−y2) d. x= t cosθ; y= t sinθ; tanθ=y/x; t= √(x2+y2)

d. x= t cosθ; y= t sinθ; tanθ=y/x; t= √(x2+y2)

Which of the following best defines a second as an SI unit of time? a. 1/60 of a minute b. the amount of time that a cesium atom needs to vibrate a specific number of times c. 1/3600 of an hour d. a brief lapse of time; a moment

the amount of time that a cesium atom needs to vibrate a specific