AZSCI Planning Investigations

Question 1

A student wants to test how the amount of sunlight affects the height of a bean plant. What is the independent variable in this investigation?

Accepted Answer

The amount of sunlight the plant receives.

Answer

The independent variable is the one factor that the investigator intentionally changes or manipulates to observe its effect. In this case, the student is purposefully changing the amount of sunlight.

Question 2

A group of students is designing an experiment to see which brand of paper towel is the most absorbent. Which of the following is the most important variable to keep constant (controlled) for each trial?

Accepted Answer

The amount of liquid poured onto the paper towel.

Answer

To ensure a fair test, all conditions except the one being tested (the brand of paper towel) must be kept the same. Pouring the same amount of liquid on each brand is critical for a valid comparison of absorbency.

Question 3

A scientist wants to investigate the effect of different types of fertilizer on the number of tomatoes produced by a plant. Which tool would be LEAST useful for collecting data in this investigation?

Accepted Answer

A telescope to observe the plants.

Answer

A telescope is used for observing distant objects, like stars and planets. It would not be a practical or useful tool for observing tomato plants in a garden or lab setting. The other tools are directly relevant to measuring plant growth and yield.

Question 4

When planning an investigation to test the freezing point of saltwater solutions, what is the best way to ensure the results are reliable?

Accepted Answer

Perform multiple trials for each salt concentration.

Answer

Reliability in a scientific investigation is increased by repeating trials. This helps to ensure that the results are not due to chance or a single error, and allows for the calculation of an average, which is a more trustworthy value.

Question 5

A student hypothesizes that a heavier ball will roll down a ramp faster than a lighter ball. To test this, they plan to release two balls of different masses but the same size from the top of a ramp. What is the dependent variable?

Accepted Answer

The time it takes the ball to reach the bottom.

Answer

The dependent variable is the factor that is measured or observed in response to the change in the independent variable. In this case, the student is changing the mass (independent variable) and measuring the time it takes to roll down (dependent variable).

(AZSCI) Arizona Science Test Practice Test

(AZSCI) Arizona Science Test Practice Test

AZSCI Planning Investigations