Kate gathered three boxes of the same size made of different materials: glass, clear plastic, and aluminum painted black. She placed them on a window sill in the sun for an hour and then measured the warmth of the air in each box.
In this experiment, what is the time of an hour?
Responses
a constant
a constant
a control
a control
an independent variable
an independent variable
a dependent variable
a constant
A student drops three blocks from the same height and measures the time it takes for the blocks to hit the ground. Each block has a different mass.
What is the independent variable in the experiment?
Responses
the mass of the blocks
the mass of the blocks
the time for the blocks to hit the ground
the time for the blocks to hit the ground
the drop height
the drop height
the volume of the blocks
the mass of the blocks
A student conducts an experiment to determine how the temperature of water affects the time for salt to dissolve in 100 mL of water. The student makes one measurement for each temperature.
What is one way that the student could improve the experiment?
Responses
perform one trial for each measurement but use a different volume of water for each test
perform one trial for each measurement but use a different volume of water for each test
use a different timer for each temperature of water
use a different timer for each temperature of water
perform multiple trials for each measurement instead of just one
perform multiple trials for each measurement instead of just one
use a different type of salt for each temperature of water
perform multiple trials for each measurement instead of just one
A student conducts an experiment to determine how the temperature of water affects the time for sugar to dissolve. In each trial, the student uses a different amount of water and a different temperature of water.
What is wrong with this experimental design?
Responses
The student did not change enough independent variables.
The student did not change enough independent variables.
The student does not have a dependent variable.
The student does not have a dependent variable.
The student needs to perform more trials.
The student needs to perform more trials.
The student changed more than one independent variable.
The student changed more than one independent variable.
Which statement best represents a proper hypothesis?
Responses
Orange popsicles taste sweeter than grape popsicles.
Orange popsicles taste sweeter than grape popsicles.
I think there is no effect on hearing if you listen to loud music only three hours a day.
I think there is no effect on hearing if you listen to loud music only three hours a day.
If two objects are dropped at the same height, the heavier object will hit the ground first.
If two objects are dropped at the same height, the heavier object will hit the ground first.
Children who wear backpacks do better academically.