Independent Variable
Define independent variable.
The factor that is purposely changed in a science experiment.
Define Dependent Variable.
The factor being measured in an experiment. It changes due to the independent variable.
Miss Velikaz bakes the same cake 3 times.
Repetition
Fredrick wanted to find out what soil works best for growing roses. He grew them in potting soil, clay, sand, and soil he found outside his yard. After one week, he measured their height and how many leaves they had.
Identify two constants
Sunlight
Type of Plant
Amount of Soil
What do engineers do?
Solve real-world problems
Inside a greenhouse, different types of trees are kept at 3 different humidity levels. These are left for 3 years. One tree is left outside in normal conditions. The heights of the trees are measured once a week.
What is the independent variable?
Inside a greenhouse, different types of trees are kept at 3 different humidity levels. These are left for 3 years. One tree is left outside in normal conditions. The heights of the trees are measured once a week.
What is the dependent variable?
Tree height
Miss Velikaz made Ms. Einhart chocolate chip cookies, Ms. Einhart liked them so much, Miss Velikaz gave her the recipe. Over the weekend, Ms. Einhart used the recipe to make 2 dozen of the cookies!!
Replication.
Fredrick wanted to find out what soil works best for growing roses. He grew them in potting soil, clay, sand, and soil he found outside his yard. After one week, he measured their height and how many leaves they had.
Identify the control
Potting Soil
How does the engineering design process start?
Identify a need
One tank of goldfish is fed the normal amount, which is once a day; a second tank is fed twice a day; and a third tank is fed four times a day during a six-week study. The fishes’ body fat is recorded daily.
What is the independent variable?
Amount of food
One tank of goldfish is fed the normal amount, which is once a day; a second tank is fed twice a day; and a third tank is fed four times a day during a six-week study. The fishes’ body fat is recorded daily.
What is the dependent variable?
Fish Body Fat
Explain the difference between repetition and replication.
Repetition the same person does repeats something. Replication, someone different does the activity.
You water some plants with 4 different types of water (salt water, regular water, sugar water and distilled water). After a two-week period, the height of the plants is measured.
Identify two Constants
Amount of light
Soil
What is a trade-off
Giving up one advantage for another.
Students of different ages were given the same puzzle to assemble. The puzzle assembly time was measured.
Identify the independent variable.
Student age
Students of different ages were given the same puzzle to assemble. The puzzle assembly time was measured.
Identify the dependent variable
Time to complete the puzzle
Mrs. Rodriguez made a new dance routine. She showed the dance routine to her 1st, 2nd, and 3rd period classes.
Repetition
You water some plants with 4 different types of water (salt water, regular water, sugar water and distilled water). After a two-week period, the height of the plants is measured.
Identify the control
Distilled water
An engineer is designing a robot. The engineer builds the first robot to test and troubleshoot problems for future robots. What is the first test robot called?
Prototype
A student measures the time it takes for a sheet of paper to fall to the ground from a marked height. The student then crumples the same piece of paper and drops the paper from the same height. The student observes that the paper fell faster the second time.
Identify the independent variable
Surface area of paper - shape of paper
A student measures the time it takes for a sheet of paper to fall to the ground from a marked height. The student then crumples the same piece of paper and drops the paper from the same height. The student observes that the paper fell faster the second time.
Identify the dependent variable.
Replication
Explain the difference between constant and control.
Constants are all factors kept the same in an experiment.
Control is the standard of comparison, it does not receive the independent variable.
What are the 5 skills of an engineer?
Think creatively
Think methodically
Use math and models
Use technology
Use science