Science Quiz Topic 1
Units:
Thing Unit Symbol
Distance Meter M
Volume Liters L
Time Seconds S
Mass Grams/ Kilograms g/ kg
Length Meters m
Speed Meters/ Second m/s
Acceleration` Meters/ Sec/ Sec m/s/s
Measurements:
Measure number: Tool
Exact number: Count/ 12 inches in 1 foot= Exact, 100cm in 1m= Exact
Q: How do you determine the last digit in any measured number?
A: The last digit is always the estimated digit.
Q: Why is the metric system called a decimal system of measurement?
A: Because each type are related by factors of 10
Q: What is the purpose of using prefixes in the metric system?
A: Easily write very large/ small measurements/ simple math by multiplying or dividing by powers.
Meterstick: cm, mm, m
Small lines on meter stick: mm
Number of significant Figures: (0.7= 1), (14=2), (159.1=4)
Making Measurements:
Observation: Information gathered by senses
Inference: An educated guess that is based on observation
Ruler: Small/short things
Meter stick: Longer/straight things
Measuring tape: Long OR curved things (Circle)
Diameter: Segment that goes through the center of circle, connects two opposite points on the circle (Maximum distance across a circle)
Radius: 1/2 Diameter, distance from the center of a circle to any point on the edge.
Circumference: Total distance around the edge of circle (Distance around a circle)
Basic equation for a straight line:)
y=mx+b
y= Dependent variable
x= Independent variable
m=slope/ b=y-intercept
Good Graph:
x and y axis with arrows
Axis title/ Descriptive title
Data points
Units on axis
Graph: 1) Draw a best fit line
2) Calculate the slope of the best fit line
3) Write the equation (y=mx+b) Distance: (slope cm/s) x (time)+ 0 for the line
Formulas:
Slope: rise/run= y2-y1/x2-x1
Percent error: accepted-measured/ accepted x 100
Circumference: c (circumference) = π x d (diameter)
Speed: Distance/time Average speed: Total Distance/ Total time
List of common speed:
Neighborhood speed: 25 mph
x times 0.4472= ________m/s
Dimensional analysis:
Units to convert measurements and check that the answer has the correct units.
① Given value → ② Multiply Conversion factor → ③ same units cancel → ④ Check right unit