Required Practical: Investigating Force & Extension Flashcards

All 6 cards in this deck

What are the steps of the required practical investigating the relationship between force and extension for a spring?

e.g. using 1 N weights hung from a clamped spring

1. Clamp the spring and measure its original length with a ruler.
2. Add weights one at a time, recording the force and the new length each time.
3. Work out extension = new length − original length and plot force against extension.

In the required practical on force and extension, what are the independent, dependent and control variables?

Independent: force (weight) applied; dependent: extension of the spring; control: the same spring throughout.

Name one hazard in the force–extension practical and how to reduce the risk.

Falling masses (or the spring snapping) — wear eye protection and place a mat/tray below, keeping feet clear.

What are the steps to find the extension of a spring from measured lengths?

e.g. original length $5.0$ cm, length with load $7.5$ cm

1. Measure the original (unloaded) length: $5.0$ cm
2. Measure the length with the load attached: $7.5$ cm
3. Extension = loaded length − original length $= 2.5$ cm

What is an anomalous result in a force–extension investigation, and what should you do about it?

A result that does not fit the pattern (lies far from the line of best fit); repeat that measurement and exclude it from any mean.

Name one way to improve the accuracy of the length measurements in the force–extension practical.

Read the ruler at eye level, using a pointer or set square, to avoid parallax error.