What are related variables? Oftentimes, we see situations where

two variables are related.

For instance, the hotter the temperature outside, the more energy an electric plant has to provide.

What are related variables? The more a person lifts weights, the

stronger they get

The louder your parents yell at you, the less you listen

What’s another?

What are related variables? These variables are said to be

related. They are related because one of them is a function of the other –

for instance, how much you tune out your parents is a function of how loud (or how often) they yell

What are related variables? How strong you get is a function of

how hard you work when you lift weights

When one variable is a function of another, those two variables are related

What are related variables?• The variable that is a function of

another is called the dependent variable

• The variable that “causes” the other to happen is called the independent variable

Independent v Dependent variables

• The harder you work when you lift weights, the stronger you get

• What are the two variables?• how hard you work• how strong you get

• Which one is a function of the other?

Independent v Dependent variables

• The harder you work when you lift weights, the stronger you get

• How strong you get is a function of how hard you work – so…

• how strong you get is the dependent variable

• how hard you work is the independent variable

Bungee Jumping

Bungee Jumping 2

One more

In your groups, design an investigation in which you test the effect of different weights on the amount of stretch on a bungee cord.

Bungee cord: rubber bands with paperclip on end

weight: use masses provided (hook onto paperclip)

* Total number of rubber bands used should not change

* Weights should not strike the ground (that wouldn’t be too safe)

On Your Own (OYO)

pg 101 a – d

Modeling• As a group, consider the situations

described on pg 102 (MORE #1)

• Create one answer sheet for your group on notebook paper, and answer questions a – d; if you use a table or a list as an answer, be sure to title your list/headings so that other people will understand what you are writing

• Follow the directions and as a group, create a coordinate graph on poster paper that reflects the effect of the price charged on the number of customers

Density

density of a property of matter that depends on two variables: mass volume

Mass is measured on a scale (we’ll use grams)

Volume of regular shapes is found by multiplying length x width x height

Density Sample Problem

The mass of a piece of wood is found to be 35 grams

The wood measures 15 cm wide, 2 cm thick, and 4 cm long

draw a labeled diagram that represents this piece of wood and solve the problem

Density Lab

Does the size of a piece of wood affect its density?

In your groups, design a method to answer the following question. One rule: you must use at least five different sizes of wood.

Density Lab Assessment On your own, create a report that

contains: lab question short explanation describing mass, volume, &

density + formula list of steps group followed that includes each

team members responsibilities data table will contain at least five different

trials data will have all appropriate units graph of data is properly created and labeled conclusion is reached and results are

explained