RAD 141 Week 2

In physics which of the following is not a fundamental standard of measurement?

Speed

In physics, which of the following is a fundamental unit (not a derived unit)

Centimeters

If a 50 kilogram body is moved from outer space down to earth, its mass will

remain the same

The mass of a small object, such as a pencil or pen, would be best measured using

Grams

The interactions between all matter in the universe are governed by _____ different forces

4

Anything that enters a “push” or a “pull” such that it can cause a change in motion of another body may be described as

A force

To hold together the nucleus of an atom, the strong nuclear force must overwhelm

Electrical force

One-thousandth of a millimeter would be a(n)

Micron or micrometer

A million volts would be on

Megavolt

Which of the following is about the width of your smallest fingernail?

One centimeter

Which unit is equivalent to one 10-billionth of a meter?

The angstrom

The wavelength of x-rays may best be described as

A fraction of an angstrom

Approximately how many centimeters is the standard distance of the x-ray tube from the Bucky when performing tabletop radiographic procedures?

100

A fluoroscopic examination is conducted using 1.5 A (amperes) of electricity. That is equivalent to

1500 mA

The generic unit of energy is the

Joule

Which of the following represents the conversion of kinetic energy into potential energy

Lifting a book up off the table

As an electron drops down into lower atomic shell, its positional form of potential energy is emitted as a(n) ______ form of potential energy

Electromagnetic

If an object is lifted from 10 meters to 20 meters above the ground, it will have

Twice as much potential energy

In “closed systems” such as the universe, laws of conservation demand that

Total energy must be equal before and after an event

One correct interpretation of Einstein’s famous equation “E =mc² “

Energy cannot be created nor destroyed

Which of the following is not a form of energy

Work

The energy that would be released by complete annihilation of any particle of matter is referred to as the particle’s

Rest energy

Any device that can change one form of energy into another is called a(n)

Transducer

At the molecular level, sound and heat are actually both forms of

Kinetic energy

If a textbook that is suspended 2 feet above your desk possesses 6 joules of potential energy relative to the desk, and is dropped, how much kinetic energy will it have when it reaches a point ½ foot above the desk?

4.5 Joules

A substance which occupies a definite volume of space but does not retain a definite shape would be a

Liquid

Pascal’s law explains how liquid pumps (such as the human heart or the brakes on your car) work: applied pressure will be transmitted undiminished throughout any liquid because liquids

Resist compression

Condensation results in a(n)

decrease in potential energy

Heat is defined as the flow _____ from one substance to another

Internal energy

Temperature measures the _____ of the molecules

Average kinetic energy

At the moment a liquid changes state into a gas, it changes

Potential energy

Heat transfer by convection is restricted to

Fluids

Most of the heat energy produced in an x-ray tube during an exposure is released by

Convection

in the x-ray rube, an example of heat dispersion by conduction is

Warping of metal ball bearings in the shank of the anode

The dewars in an MRI machine keep the temperature of its super conducting magnetic coils at 4 degrees above

Absolute zero

The only kind of heat transfer that can take place through vacuum space is

Radiation

A bowling ball is dropped from the leaning tower of pisa at a height of 21 meters. At this height its potential energy relative to the ground is 30 Joules. What is the kinetic energy of the ball when it reaches a point 7 meters above the ground?

29 Joules

Toothpaste flows out of a tube squeezed at the far end because

Liquids cannot be compressed

The molecules of a gas

Are not held in fixed positions relative to each other

The unit of force is the

Newton

Which of the following numbers is the same as 10 raised to the minus 6th power

1/1,000,000

Heating a substance can lead to two results: it will either increase the temperature OR

Increase the potential energy

When snow is forming from droplets of water in a cloud, the surrounding air

Is warmed

40 ms = _____ seconds

0.04