Unit 1 Lecture

Chapter 1 and 2

Units

Worldwide we use the metric system to measure

Distance in meters

Mass in grams

Time in seconds

Volume in liters

Measuring

Metric system (SI System) based on units of 10

Kilo = 1,000

Deca = 10

Centi = 1/100 or 0.01

Milli = 1/1000 or 0.001

Units of Length

1 meter = 1,000 millimeters (mm)

1 meter = 100 centimeters (cm)

1000 meters = 1 kilometer (km)

We always use millimeters, centimeters , and meters.

We do NOT use inches and feet.

Mass

Mass = amount of matter in something

Mass is measured in grams

We use digital scales to measure mass

Ex: My toy truck has a mass of 25 grams.

Weight

Mass is needed in order to calculate weight.

Mass is the amount of matter something has.

Weight is that amount of matter multiplied by gravity.

Your mass stays constant, but your weight changes on different planets.

Volume

Volume is the amount of space an object takes up.

Volume is measured in liters.

We use graduated cylinders to measure the volume. Each line is a milliliter.

Meniscus

When you are reading the volume in a graduated cylinder, the liquid may have a curve at the top.

This curve is a meniscus.

Read from the bottom of the meniscus.

Measuring Area

Length x width = areaL x W = AreaLength is the longest sideWidth is the shortest sideArea is in units squaredEx: m2 or cm2

Measuring Volume

Length x width x height = volume

L x W x H = Volume

Volume is in cubed units

Ex: L3 or cm3

Measuring Temperature

Amount of heat something can contain

Thermometers use mercury or colored alcohol inside a tube

When the liquid gets hot, it expands and therefore the temperature is higher

Temperature Scales

There are 3 temperature scales:

1. Fahrenheit

2. Celsius

3. Kelvin

Analyzing Data

We use charts

Bar Graphs

Pie charts

Line graphs

All of these show data that has been collected0

10

2030

40

5060

70

8090

1stQtr

2ndQtr

3rdQtr

4thQtr

EastWestNorth

Line Graphs

Line graphs are used to show change in a variable over time

The horizontal axis is the x- axis

The vertical axis is the y- axis

Time is always on the x- axis

The Scientific Method

1. Find an issue, observe

2. Form a hypothesis (a statement)

3. Experiment

4. Record data (use a chart)

5. Analyze your data

6. Conclusion

7. Write out lab report

Hypothesis

A hypothesis is a testable statement.

Usually it involves “If, then”

Ex: If I water my plants with milk, then they will grow less tall than if I used water.

Constants vs. Variables

In each experiment you should have many constants and only one variable.

Constants will remain the same.

The variable will change.

Ex: The plants, dirt, time, temp stay constant

The milk vs. water is the variable