physics Flashcards
exact values
have infinite number of significant digits
it includes:
counted values-directly counted (ex 20 cats)
defined values-always true,constant measures
accuracy
&precision
- accuracy measures how close a measurement is to the actual value
it is expressed as a percent value
poor accuracy results from flaws in equipment or procedure
Precision measures repeatability or consistency
it is expressed as the accepted value
poor precision is caused by the experimenter
what is a scalar quantity
any quantity that has magnitude(size),but no direction ex. distance types of speed speed calculations distance-time
vector quantity
a quantity that has magnitude( a size,number) and direction. Direction is shown by drawing an arrow above the unites symbol
what are the three types of speed
CONSTANT SPEED
aka uniform motion
an object traveling at a constant speed is moving at the same speed for a period of time
AVERAGE SPEED
the total distance over total time
INSTANTANEOUS SPEED
the speed at a particular moment in time
it is not affected by an objects previous speed of how long it has been moving
acceleration
symbol = a
units are m/s or km/h/s
it is a measurement of the rate of change in speed per unit of time