Chapter 2 - Measurements and Calculations Flashcards
How many base units does the SI system have?
Seven
What is a quantity?
Something that has magnitude, size, or amount
What is mass?
A measure of the quantity/amount of matter
What is weight?
A measure of the gravitational pull on matter
What is length?
A measure of distance
What do combinations of SI form?
Derived units
What is volume
The amount of space occupied by an object
What is density?
The ratio of mass to volume
D = m/v
What is a conversation factor?
A ratio derived from the equality between two different units that can be used to convert from one unit to another
What is dimensional analysis?
A mathematical technique that allows you to use units to solve problems involving measurements
The Factor-Label Method
H-bar
What is accuracy?
The closeness of measurements to the correct or accepted value or the quantity measured
What is precision?
The closeness of a set of measurements of the same quantity made in the same way
How do you calculate percentage error?
Subtracting the accepted value from the experimental value, dividing by the accepted value, then multiplying by 100, then take the absolute value
|(Value(ex) - value(acc)/value(acc) * 100|
What are significant figures?
All the digits known with certainty plus one final digit, which is somewhat uncertain or estimated
How do you know if two quantities are directly proportional?
If dividing one by the other gives a constant value
As one goes up, the other goes up
As one goes down, the other goes down
Straight positive line
