What is the independent variable in the graph below?

• Speed (m/s)
• Time (s)

What is the dependent variable in the graph below?

• Population (as a % of carrying capacity)
• Time

Two groups of students were tested to compare their speed working math problems. Each group was given the same problems. One group used calculators and the other group computed without calculators. What is the control in this experiment?

• Two groups of students.
• Speed working math problems.
• Each group was given the same problems.
• Group with calculators.
• Group without calculators.

An experiment was performed to determine how the amount of coffee grounds could affect the taste of coffee. The same kind of coffee, the same coffee maker, the same amount and type of water, the same perking time, and the same electrical sources were used. The statement saying, "the same coffee maker " is an example of

• the independent variable.
• the dependent variable.
• a constant.
• the control.

The graph above represents an

• endothermic change because as time goes by temperature increases.
• endothermic change because as time goes by temperature decreases.
• exothermic change because as time goes by temperature increases.
• exothermic change because as time goes by temperature decreases.

Vaporization (boiling) is occurring at

• 0 C.
• 50 C.
• 100 C.

In this type of phase change, particles are

• speeding up
• slowing down

The graph above represents an

• endothermic change because as time goes by temperature increases.
• endothermic change because as time goes by temperature decreases.
• exothermic change because as time goes by temperature increases.
• exothermic change because as time goes by temperature decreases.

In this type of phase change, particles are

• moving closer toghter
• spreading further apart

According to the graph, which item would most likely float on top of water?(less dense)

• Gold
• Aluminum
• Iron
• Gasoline