Categoric variables come in distinct types. Continous variables can take any value on a numerical scale.
Bar charts are used when the variable you changed in an experiment is categoric.
An effective lubricant reduces the friction force.
A conclusion states what you found out in an experiment and also explains how you know.

Common misconception

The type of graph chosen to represent data can just be personal choice.

Specific kinds of graph should be chosen to represent specific kinds of data.

Keywords

Lubricant - A lubricant is a substance added between two surfaces to reduce friction.
Friction - Friction is the force of one surface gripping or rubbing on another.
Categoric - A variable is categoric if it comes in distinct, separate categories.
Continuous - A variable is continuous if it can take any value, including decimals, on a scale of numbers.
Conclusion - A conclusion states what you found out in an experiment and explains how you know.

You could bring in a bike and some oil/grease to apply to the chain to demonstrate lubrication. The task focusses on snowboarding but links could also be made to skateboarders using wax on their boards or on curbs or rails to perform 'grind' tricks.

Teacher tip

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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Worksheet

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Starter quiz

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6 Questions

Q1.

Which picture shows a bar chart?

Correct Answer: An image in a quiz

Q2.

In an experiment, anything that could change (vary) between tests is called a ...

Correct Answer: variable, Variable, variable., Variable.

Q3.

Which option correctly describes what an experiment conclusion should contain?

A conclusion should contain the practical steps needed to do an experiment.

A conclusion should contain all the data collected in an experiment.

Correct answer: A conclusion should contain what you found out and explain how you know..

Q4.

Which kind of force does a lubricant reduce?

gravitational forces

drag forces

Correct answer: friction forces

magnetic forces

Q5.

Which one of these variables comes in different categories?

length of fish

mass of fish

Correct answer: type of fish (species)

number of fish (population size)

Q6.

Identify the possible benefits of lubricating moving parts of a system, to reduce the friction.

Correct answer: Lubricated moving parts would be smoother and quieter.

Lubricated moving parts would be greasy to touch.

Correct answer: Lubricated moving parts would wear down less over time.

Correct answer: Lubricated moving parts would need less force to keep moving.

Q1 image 2 UYSEG Q1 image 3 UYSEG

Exit quiz

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6 Questions

Q1.

A is any substance added between two surfaces to reduce the friction forces.

Correct Answer: lubricant

Q2.

Which part of an experiment write-up states what you found out and explains how you know?

method

table of results

graph (usually a bar chart or line graph)

Correct answer: conclusion

Q3.

Which of the below is the name for a variable that comes in distinct, separate types or categories?

Correct answer: categoric variable

continuous variable

control variable

grouped variable

Q4.

Jun did an experiment to test how far objects slide across a surface lubricated with different lubricants. His results are in the table. Which of the below is a correct conclusion from Jun's results?

Wood polish was the best lubricant and hand soap was the worst.

Wood polish was the best lubricant because friction was the lowest.

Correct answer: Hand soap was the best lubricant and wood polish was the worst.

Hand soap was the best lubricant because friction was the highest.

Q5.

Izzy tested how far masses slide with different lubricants. The mass slid 53 cm on cooking oil, 40 cm on washing-up liquid and 33 cm on water. Which is the best bar chart of these results?

Bar chart 1

Correct answer: Bar chart 2

Bar chart 3

Bar chart 4

Q6.

Laura tested how far different shaped 100 g masses slide across the same surface. Her results are shown in the table. Which option correctly explains what type of graph Laura should draw?

Correct answer: A bar chart because 'shape of 100 g mass' is a categoric variable.

A line graph because 'shape of 100 g mass' is a categoric variable.

A bar chart because 'distance travelled' is a continuous variable.

A line graph because 'distance travelled' is a continuous variable.