# Guidance for OCR Twenty First Century Science - Controlled Assessed Investigation

I downloaded the OCR specimen task for the controlled assessed practical investigation. I did the task as if I were a student including writing it up; then I marked it as teacher. The pdf is an annotated version of my work, showing where I think I earned the marks.

Lots more guidance here: http://www.myphysics.org.uk/ks4cacswk.htm

Hope you find this useful.

HideShow resource information

## Pages in this set

### Page 1

Motion of a Vehicle on a Surface
There are several factors that can affect the motion of a vehicle on a surface.

We need to consider the forces that are acting on the vehicle and the mass of the vehicle. It might be useful
to think about the momentum of…

### Page 2

KEslow = ½ m x v2 = 0.5 x 0.4 x 9 = 1.8 J

KEfast = ½ m x v2 = 0.5 x 0.4 x 36 = 7.2 J

Say the counter force from rolling over the carpet is 6N, then the distance each one should travel can be…

### Page 3

The spread of these results is from 0.105 to 0.107 ­ only 2 ms difference between the highest and the lowest
reading. This is much better than timing with a stopwatch. Timing 0.1 of a second with a stopwatch would not
be very reliable ­ human reaction time is not…

### Page 4

A184 Controlled Assessment Practical Investigation Mon YEAR

Name: Ally Davies Date: 23 May 2012

Title of activity: Motion of Vehicle on Slope

Hazards: Suggested Control Measures:
Slope could fall Hold in place with clamp

Trip hazard from equipment on floor / trailing leads Make sure all equipment is on desk…

### Page 5

Controlling Risk

In this experiment there are few hazards and the risks they present are low. The board I am using as a ramp
might fall from its position. It is sensible to keep fingers and feet out of the gap under the ramp, just in case it
does slip,…

### Page 6

Analysis

How stopping distance is affected by the start speed
110

100

90
Marking:
large scale axes
80 axes labelled with title and units
good for A6
Stopping Distance (cm)

70

60

50 Marking:
points accurately plotted
graph shows good line of best fit
40 good for A6

30

Marking:…

### Page 7

I collected data over a good range (ramp runs from 5 cm to 40 cm), but the speeds and the stopping distances
didn't actually change very much. I did 3 repeats for each ramp run length and I was careful to line everything
up so it was repeatable. I kept…