Warm Up On a sheet of paper this

Warm Up On a sheet of paper (this can be scrap or share a page with someone) define: • Independent Variable • Dependent Variable • Constant • Hypothesis

Variables, Controls Constants

Identify the Variables There are two kinds of variables we will be using to create a line graph: Independent / (Manipulated ) Variable – this is the variable that we change. Dependent / (Responding) Variable – this is the variable that responds to that change.

Identify Constants in an Experiment Constants are things in an experiment that stay the same. There are many things in an experiment that are constant. Most things in your experiment should be constant.

Identify the Control in an Experiment The control is a particular sample that is treated the same as all the rest of the samples except that it is not exposed to manipulated variables Common examples: • Room Temperature • Water • No weight added or removed • No protection

Example 1 Jason believed that oil poured faster when it was warmer. He created an experiment where he warmed the oil to different temperatures and timed how long the oil took to fill a beaker to 50 m. L.

Independent/ Manipulated Variable – temperature of oil. Dependent/ Responding Variable – Time it took to fill a 50 m. L beaker Constants – beaker , type of oil, amount of oil …… Control – room temperature oil.

Example 2 Adam thought that the heavier a person was, the faster they would be able to roller blade down a hill. He created an experiment to see if he was correct. He got a skateboard and timed how long it took to reach the bottom of the hill. He then put different weights on the skateboard and timed how long it took to reach the bottom of the hill.

Independent/ Manipulated Variable – amount of weight Dependent/ Responding Variable – time to reach bottom of the hill Constants – type of skateboard, location of run …. . Control – Time without the weights

Example 3 Emilio believed that the more someone exercised the faster their heart would beat. He created an experiment that had 25 of his friends running in place. He timed their heart rate when they started running and then every 15 seconds for 30 minutes.

Independent/ Manipulated Variable – Portion of the exercise (beginning, middle, end) Dependent/ Responding Variable – Heartbeat Constants – Type of exercise, pace of exercise, the time of day they ran , the temperature ……. Control – Heart rate before exercise

Example 4 Jenny ‘s mom was telling her a story about how her grandmother would always add aspirin to the water before watering her plants. Jenny decided she would find out if it really made a difference and thought it probable did. Jenny hypothesized that the more aspirin she used, the more the plants would grow. She conducted an experiment with 4 different amounts of aspirin (including one without aspirin) and she used 10 bean plants for each amount. She used the same size pot, types of plants, water amounts, dirt, etc….

Independent/ Manipulated Variable – amount of aspirin. Dependent/ Responding Variable – plant height. Constant – type of plant, amount of light size of pot……. Control – The plant with no asprin.