CHAPTER 2:FUNDAMENTALS OF RADIOLOGIC SCIENCE

What is physics?

The study of interactions of matter and energy.

Which three are the base quantities of measurement?

Mass, length, and time.

A quantity formed by combining one or more base quantities is called a:

Derived/secondary quantity.

Which are considered special quantities in radiologic science?

Exposure, dose, equivalent dose, and radioactivity.

What does IBWM stand for?

International Bureau of Weights & Measures.

What is the SI unit of length?

Meter.

According to the summary, the modern definition of one meter is based on:

The distance traveled by light in a specified fraction of a second.

The standard unit of mass in the SI system is:

Kilogram.

Which are units of weight?

Newton and pound.

Modern measurement of time is based on:

Vibration of cesium atoms.

The original definition of time was based on:

Earth's rotation on its axis.

Which of the following is NOT one of the four systems of units listed?

MRI.

Mechanics is the segment of physics concerned with:

Objects at rest and objects in motion.

The study of objects at rest is called:

Statics.

The study of objects in motion is called:

Dynamics.

Velocity is the:

Rate of change of position with time.

What is the velocity of light?

3 × 10⁸ m/s.

Acceleration is the:

Rate of change of velocity with time.

An object moving at constant velocity has:

Zero acceleration.

Who presented the fundamental laws of motion?

Isaac Newton.

Newton's First Law is also known as the law of:

Inertia.

Newton's First Law states that a body will remain at rest or continue moving with constant velocity unless:

An external force acts on it.

Inertia is:

The property of matter that resists a change in its state of motion.

Newton's Second Law is primarily the law of:

Force.

What is the SI unit of force?

Newton.

A force is BEST described as:

A push or pull on an object.

Newton's Third Law is the law of:

Action/reaction.

Newton's Third Law states:

Every action has an equal and opposite reaction.

Weight is:

A force caused by gravity acting on a body.

Momentum is the:

Product of mass and velocity.

Work is defined as:

Force applied times distance.

What is the SI unit of work?

Joule.

Power is the:

Rate of doing work.

What is the SI unit of power?

Watt.

One horsepower is approximately:

746 W.

Energy is:

The ability to do work.

The law of conservation of energy states that energy:

May change from one form to another but cannot be created or destroyed.

The two forms of mechanical energy are:

Kinetic and potential.

Kinetic energy is the energy associated with:

Motion.

Which equation represents kinetic energy?

KE = ½mv².

The SI unit of kinetic energy is:

Joule.

Potential energy is:

Stored energy of position or configuration.

Heat is:

Kinetic energy of the random motion of molecules.

What unit is used for heat in the summary?

Calorie.

One calorie is the amount of heat necessary to raise the temperature of:

1 g of water by 1°C.

Which combination represents the three methods of heat transfer?

Conduction, convection, radiation.

Heat transfer through a material by touching is:

Conduction.

Mechanical transfer of "hot" molecules in a gas or liquid is:

Convection.

Transfer of heat through emission of infrared radiation is:

Thermal radiation.

An x-ray tube cools primarily by:

Radiation.

Which instrument is used to measure temperature?

Thermometer.

Which three temperature scales are listed?

Celsius, Kelvin, Fahrenheit.

Convert 68°F to Celsius.

20°C.

Convert 20°C to Fahrenheit.

68°F.

What is the approximate Kelvin temperature of 0°C?

273 K.

Cryogens are:

Cooling agents used in MRI.

Liquid nitrogen boils at approximately:

77 K.

Liquid helium boils at approximately:

4 K.

Which four traditional radiologic units are listed in the summary?

Roentgen, rad, rem, Curie.

The Roentgen is a unit of:

Radiation exposure/intensity.

The Roentgen applies specifically to:

X-rays and gamma rays interacting with air.

What is the symbol for Roentgen?

R.

The SI unit corresponding to exposure is:

Air kerma.

The rad is the unit of:

Absorbed dose.

The rad refers to the quantity of radiation:

Received/absorbed by the patient.

Unlike the Roentgen, absorbed dose can be used for:

Any type of ionizing radiation and exposed matter.

The SI unit of absorbed dose is:

Gray.

The rem is the unit of:

Equivalent dose.

Equivalent dose is primarily used to express radiation received by:

Radiation workers and populations.

The SI unit of equivalent dose is:

Sievert.

Occupational radiation monitors use which quantity?

Rem/equivalent dose.

The Curie is a unit of:

Radioactivity.

Radioactivity refers to the:

Quantity of radioactive material/activity.

The SI unit of radioactivity is:

Becquerel.

One Curie equals approximately:

3.7 × 10¹⁰ disintegrations per second.