Science Skills Manual

Question 1

Describe one control variable to ensure a valid experiment

Answer 1

Controlled variable should be the object that is actually moving.
Reason: One controlled variable would be the (object) used. Controlling this variable ensures a valid experiment as if different (object)s with different (characteristics) are used the impact of forces such as air resistance will alter results, creating more than 1 independent variable making the experiment invalid.

Question 2

When given calculate question

Answer 2

Use relevant significant figures
In working out, put measurement

Question 3

How to address reliability

Answer 3

Multiple trials/ repetitions to calculate averages or identify outliers

Question 4

Graphing

Answer 4

Title everything
Units everything
X points
50% graph

Question 5

Describing trend

Answer 5

As the (independent) increases/decreases
The (dependent) increases/decreases
At an increasing/decreasing rate

Question 6

Accuracy

Answer 6

Accuracy : gives exact results that are close to ideal or true value. Systematic errors: Errors associated with experimental set-up, precision of measuring device (smaller limit of reading) solved through planning and performance
Random error - Variations in measurement technique (limits of reading) solved by taking the mean of multiple measurements

Question 7

When asked to describe motion

Answer 7

Calculate the speed at associated times and make a judgement on the overall speed throughout the journey

Question 8

Reliability

Answer 8

Degree with which repeated observation and measurement taken under ideal circumstances will yield the same results.

Question 9

Validity

Answer 9

Measures what is intended. A valid experiment measures only the effects of the independent vairbale onto eh dependent variable