# Physics / Science GCSE: Investigate the effect of varying the force or mass on the acceleration of an object

This video demonstrates the GCSE Physics and Combined Science required practical to investigate the effect of varying force or mass on the acceleration of an objects included in AQA, Edexcel and OCR specifications.

The video focuses on two variables and their impact on acceleration: varying the force and varying the mass.

Students will have studied motion at KS3, but this video demonstrates which measurements they need to take and how to calculate velocity and acceleration.The equation that students will need to recall and apply - force = mass x acceleration - is featured and explained.

### Teacher Notes

The practical allows development of Apparatus & Techniques Physics 1, 2 & 3 (DfE GCSE subject content guidance, Appendix 4).

This video could be used as a way of revisiting acceleration theory before or after the carrying out the required practical.

The video demonstrates how to make valid measurements and how to use them to calculate acceleration and study the effects of changing force or mass.

The video demonstrates the measurements to take to calculate velocity and acceleration.

Students could be asked to predict the effect of increasing mass and increasing force on acceleration of an object.

This video highlights the sketch graphs generated in these investigations. These could be used to practise describing and explaining graphs.

The video also gives the opportunity to reinforce understanding of types of variable, the language of science and also identifying and justifying specific improvements.

Points for discussion:
Students need to recall and apply the equation F=ma.

Often students will use apparatus that measures acceleration directly but they also need to know how to do this manually.

This video demonstrates the measurements to make to calculate velocity and then acceleration step by step.

It also highlights a common pitfall when investigating effect of changing force in that new mass is added to the system rather than being transferred from the trolley to the hanger.

The video also focuses on specific improvements, stressing the need to explain how each of these changes is beneficial, something which students find challenging.

Language of science such as accuracy anomaly and systematic error are highlighted as part of the discussion around improvements.

Suggested activities:
Ensuring students have awareness of having a more manual approach to this investigation as well as using lightgates will be beneficial in helping them to apply to different contexts.

### Curriculum Notes

Suitable for teaching Physics and Combined Science at Key Stage 4 and GCSE in England, Wales and Northern Ireland, and at National 4 and 5 in Scotland.