Evaluate sources of uncertainty in force and extension measurements.

In the subtopic Required practical: force and extension, this learning objective focuses on evaluate sources of uncertainty in force and extension measurements. For AQA GCSE Physics 8463 Unit 4.5 Forces, keep the explanation inside Required practical: force and extension and Forces and elasticity. Approved keywords for this objective include force, extension, and uncertainty. A strong answer separates scalar and vector quantities, uses correct units where quantities are involved, and links the physical reasoning back to evaluate sources of uncertainty in force and extension measurements. This is not a generic revision point: it is specifically about Required practical: force and extension, Forces and elasticity, and the approved wording of the learning objective.