Under the new GCSE specifications in Wales, practical work in Science will be examined. This unit will help students to prepare for the practical examination.

In an experiment, A was changed and B was measured. What is the relationship between A and B?

Proportional

Directly proportional

Negative correlation

In an experiment, A was changed and B was measured. The students did not measure any data when A was set to 2. Based on the numbers in the table, what is the likely missing value when A is 2?

9

12

16

No correlation

In an experiment to measure the speed of sound over a long field, a student records four time intervals between seeing a stick being hit and receiving the sound. One reading is anomalous. The student needs to calculate the mean of the data in the most accurate way. How should they go about this?

0.73, 0.69, 0.42, 0.71

Leave the anomalous reading in and divide the total by three

Add up the readings and divide by four

Remove the anomalous reading, add the remaining readings and divide the total by three

Five groups of students have been measuring the time taken for a rubber bung to be spun round ten times when there is a weight on the other end.

They made the following table of results.

Which group has made a mistake in their measuring?

Group 1

Group 3

Group 5

Repeatable results...

are reproducible

are similar when repeated

are similar to results taken by other groups following the same method

What is the relationship between the variables A and B?

Inversely proportional

Which of these would not improve accuracy?

Taking a bigger sample size and removing anomalies

Using a bigger range of the independent variable

Using measuring instruments that can read to a greater number of decimal places

In an experiment to measure the stopping distance of a car at different speeds, what is the independent variable?

The mass of the car

The speed of the car

The tread on the tyres

Removing any anomalies, what is the mean time for 10 rotations when a force of 2 N is tested?

9.00

8.42

7.20