RAD 141 CHAPTER 3 HELP WITH MATH

What term best describes two variables in an equation that move opposite to each other up or down, but by the same magnitude - that is, when one goes up, the other goes down by the same degree

Inversely proportional

The value 0.72 expressed as a percentage is

72%

In algebra problems, the first operation is always to calculate the

Exponents

To multiply numbers with exponents

Add the exponents

Any number can be converted into scientific notation without even moving the decimal place by simply adding the phrase

X 10^0

When using dimensional analysis to make unit conversions, a critical rule to remember is that

The top units are multiplied, the bottom ones are dividing

When calculating for areas, both units and calculations must be

Squared

Because the areas of surface change less drastically (by the square) than the volumes of objects

All of the above

As the distance from the x-ray tube to the IR changes, the intensity of radiation changes

According to the inverse square of the distance

Graphs must use ______ in order to accurately represent data

a best fit line

Miliamperage (mA) is a rate just like kilometers per hour, only it describes how many electrons are traveling down a wire per second. If you use, 60 mAs for an x-ray exposure, and the exposure was 0.2 seconds, what mA did you use?

300 mA

What is 8×10^8 / 4×10^-2

2 × 10^4

How many cubic centimeters are there in 10 cubic meters?

1000 cc

X-rays, gravity, electrical charge attraction, magnetism, and other radiations all follow the inverse square law because

forces spread out over increasing areas in increasing distance

If a beam of radiation containing 1000 x-rays is spread out over a square field that measures 10cm long and 10cm wide, what is the concentration of x-rays per square centimeter?

10 x-rays/cm²

When distance between two masses is cut in half, the force of gravity attracting them together is changed to a value

Four times as large are before

Radiographer A recieves 5 mGy per second of scatter radiation standing 3 ft from the patient. What rate of radiation does radiographer B recieve standing 7ft away?

0.92 mGy/sec

A four meter cube contains how much more volume than two-meter cube?

8 times more

Solve for x: x+22=-8

-30

Solve for X: x/3 = 144/12

36

Solve for x: x = 3(8+7)²/4². - 62

-19.8

In a full scientific notation, the number is 0.0081 is

8.1 × 10^-3

What is the long-hand expression for 4.2 × 10^4

42,000

Solve for (2.6 × 10³) / (9.3 × 10^-4)

2.8 × 10^6

Convert 1700 ms into hours

0.00047hrs

How many square centimeters are there within 4 square meters?

40,000 cm²

If the radiation dose to a patient was 8 mgt at a 180 cm distance from the x-ray tube, what would the dose be if the distance were reduced to 100cm?

25.92 mGy

According to the graph below, how much radiation was required to cause 65% of a population of rats to develop leukemia?

140 gray

According to the graph below, which of the following accurately describes the x-rays in this beam of radiation?

There are 12 million x-rays having 55 kV of energy

According to the histogram graph below, how many pixels in the digital image hold a pixel value of 1280?

1700

Digital processing and calculations of the exposure indicator depend upon the identification of key landmarks, “troughs” or “Peaks” in the _____ curve that is plotted by connecting the uppermost points of each bar in the graph of the acquired histogram

Best fit

For a radiograph of a normal knee without any metal devices implanted, the acquired digital histogram will have two lobes. The second, more narrow “tail lobe” at the right represents ____ in the image

“Raw” background x-ray exposure