Making Connection

In the lab activity Making Connections, an experiment was designed to test the effect of exercise on the ability to squeeze a clothespin. The number of times the clothespin was squeezed served as the

• independent variable

• dependent variable

• hypothesis

• control

Students were asked to design a lab that investigated the relationship between exercise and heart rate. Heart rate was determined by recording the pulse rate in beats per minute. The students hypothesized that increased exercise results in an increased heart rate. The class results for the experiment are shown in the graph.

Which statement is best supported by the graph?

• Before exercising, the average pulse rate was 65; four minutes after exercising, the average pulse rate was 65.

• After four minutes of exercising, the average pulse rate was 120; two minutes after exercising, the average pulse rate was 120.

• While exercising, the highest average pulse rate was 150; before exercising, the average pulse rate was 65.

• Two minutes before exercising, the average pulse rate was 80; after two minutes of exercise, the average pulse rate was 140

Tags

NGSS.MS-PS3-5

The graph shows the average heart rate data for a group of students before, during, and after exercise. State one benefit of the increase in average heart rate during exercise.

In the lab activity 'Making Connections', an experiment was designed to test the effect of exercise on the ability to squeeze a clothespin. The number of times the clothespin was squeezed served as the

• independent variable

• dependent variable

• hypothesis

• control

Which of the following best describes the role of a control group in an experiment?

• To provide a standard for comparison

• To introduce a new variable

• To ensure the experiment is valid

• To manipulate the independent variable

In a scientific experiment, what is the primary purpose of repeating trials?

• To increase the sample size

• To verify the results

• To introduce new variables

• To reduce the cost

What is the main reason for using a double-blind study in scientific research?

• To eliminate bias

• To increase sample size

• To reduce costs

• To simplify data analysis

Which of the following is an example of a qualitative observation?

• The liquid is blue

• The temperature is 25°C

• The mass is 5 kg

• The length is 10 cm

In the context of scientific experiments, what does the term 'variable' refer to?

• A factor that can change

• A constant value

• A hypothesis

• A control group

What is the primary function of a hypothesis in scientific research?

• To provide a testable explanation

• To serve as a control

• To act as a variable

• To summarize data

Tags

NGSS.HS-PS1-2