Vocabulary
The one thing you change in an experiment
independent variable
how many independent variables can be measured in a reliable experiment?
one
An experiment is performed on plants to see how different liquids affect plant growth. Each plant in the experiment is given a different liquid; water, apple juice, or milk. Each plant has the same amount of soil, same amount of sunlight, and the same amount of liquid. In this investigation, what is the independent variable?
type of liquid
Mx. S set up an experiment to see how the mass of a ball affects the distance it rolls off a ramp. Identify the dependent variable.
distance traveled by the ball
A student is planning an experiment to find out how the height from which he drops a ball affects how high the ball bounces. What is the constant variable?
The ball used
variable that you measure in an experiment
dependent variable
When experimenting with the growth of a plant, a scientist uses three (of the same type of) plants, two different fertilizers, equal light, and equal water. What type of variable is the fertilizer?
Independent
What part of the hypothesis is the IV? Is it the "If" or the "then"?
If and it comes first
Mr. S normally uses praise as a reward to train his dog. He wants to know the best way to train his dog, so he sets up an experiment to find out if there is a better way to get his dog to respond to commands. What is his dependent variable?
amount of time dog responds to commands
Maria wants to know if birds prefer to eat in one place over another. She makes three feeders out of 2-liter bottles and paints all of them red. She fills each of the feeders with the same amount of mixed birdseed, and plans to keep the feeders out for 10 days before measuring how much seed is eaten from each feeder. She puts each of the feeders in her back yard: one feeder in a large dead tree, another feeder she sits on the dog house, and the last she sits in a small bushy tree.
What is the constant variable?
the type of birdseed
variable that remains the same in the experiment
control variable
Sabrina wants to test which brand of popcorn pops the most kernels. She picked a Giant Eagle brand, Orville Redenbacher, and PopSecret. All three bags started with the same number of kernels. She popped each for 3 minutes in the same microwave, and then counted the number of kernels left over. What is her independent variable?
brand of popcorn
Angelina performed an investigation to find out how the concentration of salt water affected the hatching of brine shrimp. What is the INDEPENDENT Variable?
Salt water concentration
An experiment is performed on plants to see how different liquids affect plant growth. Each plant in the experiment is given a different liquid; water, apple juice, or milk. Each plant has the same amount of soil, same amount of sunlight, and the same amount of liquid. In this investigation, the dependent variable is
growth of the plant
Lauren wants to know which location in her apartment is best for growing African violets. She has three African violets. She puts one on the balcony, one by the kitchen window, and one on the mantel in the living room. Each plant has the same size pot and the same soil, and Lauren gives
the plant the same amount of water. What is the constant variable?
pot size, soil type, water amount
variable that can be called "Data"
dependable variable
Mx. B's classes were testing to see which soil would support plant growth. They used the same seeds, same pots, gave the same amount of water to each, and put them all in the same location. What is the independent variable?
type of soil
David performed an investigation to find out how temperature affects crystal growth. What is the INDEPENDENT Variable?
Temperature
Jessie is concerned about how tired his classmates seem. He created a drink that he thinks will boost their energy. He recruits 100 classmates with a history of tiredness. He has 50 of them drink his new special energy drink. The other 50 drink a beverage that looks like the special energy drink, but is just water and food coloring. Both groups were told that they were getting the special drink that would boost energy. After 2 hours, 30 classmates in the first group reported having more energy and 8 classmates in the second group reported having more energy.
What is the dependent variable?
amount of energy
When experimenting with the growth of a plant, a scientist uses three (of the same type of) plants, two different fertilizers, equal light, and equal water. What type of variable is the water?
constant
definition of independent variable.
the variable that is being tested
the variable that is changed in an experiment
Mx. B's classes were testing to see which soil would support plant growth. They used the same seeds, same pots, gave the same amount of water to each, and put them all in the same location. What is the control variable?
same seeds, same pots, same amount of water, same location
Kira wants to test which type of soda creates the biggest foam explosion when adding a Mentos candy. She chose Sprite, Coke, and Mountain Dew. One at a time, she added a single Mentos candy and measured the height of the foam eruption. Mountain Dew created a foam eruption of 7 inches. Coke and Sprite tied at 5 inches. What is her independent variable?
type of soda
How does watching TV during studying affect a student’s test grades? Which variable is italicized?
dependent variable
Pat performed an investigation to find out under which color of light plants grow best. What variable should be constant?
the color of light received
the amount of light the plant received
the number of different colors of light tested
nothing needs to be controlled
the amount of light the plant received