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40 Cards in this Set
- Front
- Back
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Give a definition of Physics. |
Physics is the study of the interaction of matter and energy in all their forms. |
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In Mechanics what three measurable quantities are considered Basic?
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1. Mass
2. Length 3.Time |
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What are Secondary Quantities also called?
Why? |
Derived Quantities.
They are derived from combinations of the Basic Quantities. |
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What are Special Quantities?
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They are Quantities that support measurement in specialized areas of science.
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Give four Special Quantities used in Radiology.
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1. Exposure
(Roentgens/Air Kerma) 2. Dose ( (Rad/ Gray) 3. Effective Dose (Rem/Sievert) 4. Radioactivity (Curie/Becquerel) |
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Give four systems of units.
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1. SI -System Internationale
2. MKS -Meter-Kilogram-Second 3. CGS -Centimeter-Gram-Second 4. British -Foot-Pound-Second |
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What are the SI and British units of Length?
What is their relation? |
1. Meters: 1m = 3.28f
2. Feet: 1f = .3m |
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How is the meter defined?
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The distance traveled by light in 3 x 10⁻⁹ seconds.
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What is the SI unit of Mass?
How does it differ from the British unit? |
1. Kilogram
2. The British Pound is a unit of Weight (Gravity acting on it) |
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What is the SI & British unit of Time?
What is it based on? |
1. The Second
2. It is based on the vibrations of Cesium (Ce) atoms. |
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What is the definition of Mechanics?
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A segment of Physics that deals with objects at rest (Statics) and objects in motion (Dynamics).
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What is the definition of Velocity.
What is its formula? |
The rate of change of Position with time.
v = d/t |
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What is the formula for Average velocity?
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v⁻ = (vo + vf)/2
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What is the definition of Acceleration?
What is its equation? |
The rate of change of Velocity with Time.
a = (vf -Vo)/t |
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What is Newton's First Law?
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A body will remain at rest or continue to move with constant velocity in a straight line unless acted upon by an external force.
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What is another name for Newton's First law?
How is this new term defined? |
The Law of Inertia.
The property of matter that acts to resist a change in its state of motion. |
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What is Newton's Second Law?
What is its equation? |
The Force (F) acting on an object with Acceleration (a) is equal to the product of its Mass (m) and the Acceleration produced by the Force.
F = ma |
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What is the SI unit of Force?
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The Newton
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What is Newton's Third Law?
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For every Action there is an equal and opposite Reaction.
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Define Weight.
What are the SI and British units for the Constant now introduced? |
Weight (Wt) is the Force on a body caused by the downward pull of Gravity on it.
SI: g = 9.8m/sec/sec British: g = 32ft/sec/sec |
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What is the equation for Weight?
What is the equivalence between SI and British units. |
Wt = mg
1 lb = 4.5 Newtons |
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Define Momentum.
What is its equation? |
Momentum is the product of a body's mass (m) and its velocity (v).
p =mv |
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Define Work.
What is its equation? What is its Unit? |
Work (W) is the product of the Force (F) applied and the Distance (d) over which it is applied.
W = Fd Joules (J) |
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Define Power.
What is its equation? What is its Unit? |
Power (P) is the rate of doing Work
Or: Power is the quotient of work by Time. P = Fd watts (W) = mad |
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State the Law of Conservation of Energy.
How is energy defined? |
Energy cannot be created or destroyed but can be transformed from one form to another.
Energy is the capacity to do work. |
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What are the two forms of Mechanical Energy?
How are they defined? |
Kinetic Energy (KE): Energy by virtue of the motion of an object.
Potential Energy (PE): Energy by virtue of an object's position. |
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What are the two equations for energy?
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KE = 1/2(mv2)
PE = mgh (h is height above the earth's surface) |
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How is Heat defined?
What is its Unit? |
Heat is the kinetic energy of the random motion of molecules.
The Calorie |
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If one object has more heat than another what can be said about it?
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The motion of its molecules are more rapid and disordered than the other's.
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How can heat be transferred?
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1. Convection
2. Conduction. 3. Radiation. |
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Define Conduction.
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The transfer of heat through a material, or by touching.
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Define Convection.
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The mechanical transfer of heat by movement of 'hot' molecules in a gas or liquid from one place to another.
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Define Radiation (of Heat)
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Thermal Radiation is the transfer of heat by the emission of infra-red radiation.
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Define Temperature.
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a. The degree of hotness or coldness of a body or environment.
b. A measure of the average kinetic energy of the particles in a sample of matter, expressed in terms of units or degrees designated on a standard scale. |
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What are Scalar and Vector quantities?
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Scalar: refers to a quantity, such as mass, length, or speed, that is completely specified by its magnitude and has no direction.
Vector: refers to a quantity, such as velocity, that is completely specified by a magnitude and a direction. |
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What are the three types of temperature scale?
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1. Celsius (c)
2. Fahrenheit (f) 3. Kelvin (k) |
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What is the equation to convert Fahrenheit to Celsius?
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Tc = 5/9(Tf-32)
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What is the equation to convert Celsius to Fahrenheit?
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Tf = 9Tc/5 + 2
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What is the equation to convert Celsius to Kelvin?
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Tk = Tc + 273
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What is the word for extremely cold liquids?
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Cryogens.
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