1. 2.1 Space and Time 1

2. Chapter 2 Objectives Express lengths in metric and English units.
Convert measurements and calculated quantities between different units.
Calculate the surface area and volume of simple shapes and solids.
Work with time intervals in hours, minutes, and seconds.
Describe two effects you feel every day that are created by mass.
Describe the mass of objects in grams and kilograms.
Use scientific notation to represent large and small numbers.
Design a controlled experiment.
Create and use a graphical model based on data.

3. Chapter 2 Vocabulary element English system experimental variable
exponent
friction
gas
graph
graphical model
independent variable
inertia
length
liquid
mass
metric system
mixture
plasma
precision
procedure
scientific notation
SI system
solid
speed
surface area
time interval
variable
volume
weight
x-axis
y-axis

4. Inv 2.1 Distance and Length
Investigation Key Question:
How do we accurately communicate length and distance? 4

5. 2.1 Space and Time
Space in physics means the three dimensions of up-down, left-right, and front-back.
The three dimensions of space are described with length units, such as meters, inches, and feet.
Time provides another dimension for describing when something occurs.

6. 2.1 Thinking about distance
Measurement
is a quantity and a unit
Distance
is the amount of space between two points
is measured in units of length

7. 2.1 Two common systems of units
Science problem solving requires both:
Metric or S.I. system
English system

8. 2.1 Two common systems of length
Almost all fields of science use metric units.
They make calculations easier because the units are based on factors of ten.

9. 2.1 Converting from one unit to another
It is often necessary to take a measurement in one unit and convert it into a different unit using conversion factors.

10. Converting length in yards to meters
A football field is 100 yards long. What is this distance expressed in meters?
You are asked for the distance in meters (m).
You are given the distance in yards (yds).
Relationship: 1 yard= 3 feet
100 yds x 3 ft x m = m
1 yd 1 ft

11. 2.1 Time Two ways to think about time:
What time is it?
11:52 a.m. on March 12, 2010
How much time has passed?
2 hr: 22 min: 42 sec.
A quantity of time is often called a time interval.

12. 2.1 How is time measured?

13. Converting a mixed time to seconds
How many seconds are in 1 hour, 26 minutes, and seconds?
You are asked for time in seconds.
You are given a time interval in mixed units.
1 hour = 3,600 sec minute = 60 sec
Do the conversion:
1 hour = 3,600 sec
26 minutes = 26 × 60 = 1,560 sec
Add all the seconds:
t = 3, , = 5, sec

14. 2.1 Time scales in physics
Events in the universe happen over a huge range of time intervals.
In many experiments, you will be observing how things change with time.