4. (a) Which of these is a vector quantity? A mass B force C energy D distance (b) Figure 7 shows a ball bearing as it falls slowly through a clear, dense liquid - Edexcel - GCSE Physics Combined Science - Question 4 - 2021 - Paper 1

Measurement of Appropriate Distance:

• Use a test tube filled with the clear dense liquid and mark two points on the test tube where the ball bearing will travel. Measure the distance between these two points accurately.

Measurement of Appropriate Time:

• Use a stopwatch to time how long it takes for the ball bearing to fall from the top mark to the bottom mark. Ensure to conduct multiple trials for reproducibility.

Use of speed = distance/time:

• Record the distances and corresponding times for each trial. Once you have the time for each trial, use the formula $ext{speed} = \frac{\text{distance}}{\text{time}}$ to calculate the speed of the ball bearing as it falls through the liquid.

Detail:

• It is important to repeat the measurements and average the results for accuracy. Consider noting any fluctuations in speed with different tests by varying the height from which you drop the ball bearing.

Add More Markers:

• Place additional markers at equal distances along the height of the test tube. This allows for a more detailed analysis of the speed by measuring the time it takes to pass between each marker.

Measure Time for Each Distance:

• By measuring the time taken for the ball bearing to travel different distances (from one marker to the next), you can assess how its speed changes as it travels through the liquid.

Compare Times:

• Compare the times recorded at each distance to determine if the speed of the ball bearing is consistent or varies with depth in the liquid.