Which sentence is an example of how a scientist might use a model?
options
Stopwatches measure the amount of time it takes for runners to complete a mile.
A wrench is used to tighten a nut onto a piece of wood.
Microscopes are used to magnify a group of cells on sets of slides.
Marbles placed inside a hollow sphere are used to describe protons in a nucleus.
Marbles placed inside a hollow sphere are used to describe protons in a nucleus.
Which statement best defines a universal law?
Responses
It changes over time.
It operates only under specific conditions.
It is in effect at all times.
It is in effect some of the time.
It is in effect at all times.
A student conducts an experiment to test how the temperature affects the amount of sugar that can dissolve in water. In the experiment, she uses 100 milliliters of water in each trial and stirs for five minutes each time.
What is the dependent variable?
Responses
the amount of sugar
the temperature of the water
the time stirred
the amount of water
The dependent variable is the amount of sugar.
Question
Which unit of measure is the correct SI unit to use to measure the length of a rope?
Responses
yards
yards
inches
inches
feet
feet
meter
The correct SI unit to measure the length of a rope is meter.
A student conducts an experiment to test how the temperature of a ball affects its bounce height. The same ball is used for each test, and the ball is dropped from the same height each time.
What is the independent variable?
Responses
the drop height of the ball
the drop height of the ball
the temperature of the ball
the temperature of the ball
the bounce height of the ball
the bounce height of the ball
the type of ball
The independent variable in this experiment is the temperature of the ball.
Which measuring tool should be used to measure the length of a driveway?
Responses
metric stick
metric stick
stopwatch
stopwatch
spring scale
spring scale
graduated cylinder