Identifying Variables

Half a herd of cows is given growth hormone and then compared the other half of the herd that was not given growth hormone. The cows were weighed at 2 years.

What is the independent variable?

• number of cows

• weight of cows

• amount of growth hormone

• breed of cow

Answer explanation

The independent variable is the one that is purposely changed by the experimenter. It is the cause that is being investigated.

The experimenter is changing how much growth hormone each cow receives.

Tags

NGSS.MS-LS1-5

Half a herd of cows is given growth hormone and then compared the other half of the herd that was not given growth hormone. The cows were weighed at 2 years.

What is the dependent variable?

• number of cows

• weight of cows

• amount of growth hormone

• breed of cow

Answer explanation

The dependent variable is the one that is responding to the change made and is measured for results. It is the effect that is being investigated.

The experimenter is measuring the weight of the cows as a response to the independent variable.

Tags

NGSS.MS-LS1-5

Half a herd of cows is given growth hormone and then compared the other half of the herd that was not given growth hormone. The cows were weighed at 2 years.

What is a controlled variable?

• number of cows

• weight of cows

• amount of growth hormone

• breed of cow

Answer explanation

The controlled variables are other factors that could influence the results. They must remain constant so they do not have an effect.

The breed of cow could also influence the weight so all cows must be the same breed.

Tags

NGSS.MS-LS1-5

A student wanted to test how the mass of a paperplane affected the distance it would fly. Paperclips were added before each test flight. As each paperclip was added, the plane was tested to determine how far it flew.

What is the independent variable?

• number of paperclips

• number of times thrown

• distance flown

• size of paperplane

Answer explanation

The independent variable is the one that is purposely changed by the experimenter. It is the cause that is being investigated.

The experimenter is changing the mass of the plane by adding more paperclips to the plane.

Tags

NGSS.MS-PS2-2

A student wanted to test how the mass of a paperplane affected the distance it would fly. Paperclips were added before each test flight. As each paperclip was added, the plane was tested to determine how far it flew.

What is the dependent variable?

• number of paperclips

• number of times thrown

• distance flown

• size of paperplane

Answer explanation

The dependent variable is the one that is responding to the change made and is measured for results. It is the effect that is being investigated.

The experimenter is measuring the distance the plane flew.

A student wanted to test how the mass of a paperplane affected the distance it would fly. Paperclips were added before each test flight. As each paperclip was added, the plane was tested to determine how far it flew.

What is a controlled variable?

• number of paperclips

• number of times thrown

• distance flown

• size of paperplane

Answer explanation

The controlled variables are other factors that could influence the results. They must remain constant so they do not have an effect.

The size of the plane could also influence the distance flown so all planes must be the same size.

A plumber is interested in how much water flows through a tap with different sized openings.

What is the independent variable?

• water flow rate

• size of tap opening

• water pressure

• time

Answer explanation

The independent variable is the one that is purposely changed by the experimenter. It is the cause that is being investigated.

The experimenter is changing the size of the tap opening the water is coming out of.

A plumber is interested in how much water flows through a tap with different sized openings.

What is the dependent variable?

• water flow rate

• size of tap opening

• water pressure

• time

Answer explanation

The dependent variable is the one that is responding to the change made and is measured for results. It is the effect that is being investigated.

The experimenter is measuring the flow rate of the water. The volume of water in a set time period would be measured.

Tags

NGSS.MS-PS2-2

A plumber is interested in how much water flows through a tap with different sized openings.

What is a controlled variable?

• water flow rate

• size of tap opening

• water pressure

• time

Answer explanation

The controlled variables are other factors that could influence the results. They must remain constant so they do not have an effect.

The what pressure would affect how much water flows through so the water pressure must be kept the same.

(Time is part of what is measured for the dependent variable)

An experiment was performed to see if the amount of coffee consumed affected heart rate.

What is the independent variable?

• heart rate

• fitness level of person

• resting heart rate

• amount of coffee consumed

Answer explanation

The independent variable is the one that is purposely changed by the experimenter. It is the cause that is being investigated.

The experimenter is changing how much coffee is consumed.