Physics Intro. Flashcards
What is Physics?
The branch of science concerned with the nature and properties of matter.
What is a physical quantity?
A physical quantity is a quality possessed by a system in physics that can be measured directly or indirectly
What does SI units stand for?
International System of Units.
What is the SI units built around?
7 base units,
derived units,
and a set of prefixes that act as decimal-based multipliers.
What are the International System of Units?
These are the physical quantities that must be measured directly.
What are fundamental properties?
A fundamental property cannot be defined in simpler terms other than describing how it is measured.
What are the 7 base units?
meter, kilogram, second, ampere, kelvin, mole, candala.
m, kg, s, a, K, mol, candala.
length, mass, time, electric current, thermodynamic temperature, amount of substance, luminous intensity.
What are derived units?
Derived units are formed by the powers, products or quotients of the base units and are unlimited in number.
SI units are part of the…
metric system
Symbols are used to denote…
various factors of 10 to the powers.
What is order of magnitude?
The scale of the value expressed in the metric system. Each power of 10 in the metric system represents a different order of magnitude.
What does the prefix mega mean?
mega, M, 10^6
What does the prefix kilo mean?
kilo, k, 10^3
What does the prefix deci mean?
deci, d, 10^-1
What does the prefix centi mean?
centi, c, 10^-2
What does the prefix milli mean?
milli, m, 10^-3
What does the prefix micro mean?
micro, p, 10^-6
What does the prefix of nano mean?
nano, n, 10^-9
How do you remove a prefix?
You multiply the numerical value by the value of the prefix.
How do you add a prefix?
Divide the numerical value by the value of the prefix.
How can physical quantities be divided?
They can be divided into Vectors and Scalars.
What’s a Scalar?
Scalars can be fully described only using the order of magnitude (size).
What’s a Vector?
Vectors have a magnitude and a direction. To fully describe a vector, you need to mention both magnitude and direction.
Examples of Scalars:
Mass, Time, Volume, Temperature, Pitch, Distance.
Examples of Vectors:
Displacement, Velocity, Force.
How do you know if an object is moving?
If the position of an object is not changing with time, then the object is not moving.
What is a displacement path?
The shortest path from one point to another.
Why is displacement a vector quantity?
Because one must go in a particular direction all the time.
What’s the difference between Distance and Displacement?
Distance is known as the length of a path. It is a scalar quantity. It is measured using metres (m).
Displacement is the shortest possible distance between two points. It is a vector quantity because it has a direction. It is measured in m.
What’s the difference between speed and velocity?
Speed is defined as the distance travelled per second. It is a scalar quantity.
Velocity is defined as the displacement done per second. It is a vector quantity.
What is the equation for speed?
Average speed = distance (m)/ time (s)
What’s the equation for velocity?
Average Velocity = Displacement (m)/time (s)
What is acceleration?
Acceleration is the change in velocity per second.
It is a vector quantity.
The unit is metres per square second.
What is deceleration?
When velocity is decreasing, it is known as deceleration.
The equation for acceleration:
acceleration=final velocity-inital velocity/ time
a=v-u/t
What’s another calculation for average velocity?
Average Velocity=Initial Velocity+Final Velocity/2
Average Velocity=Displacement/Time
What’s the equation to find the gradient of a line?
gradient = y1-y2 / x1-x2
