Vector graphs, scale and measurement uncertainty
≈ 48 minVector graphs, scale and measurement uncertainty
A vector graph or scale diagram is a measurement tool with limits. Choose a scale that uses most of the page without making labels unreadable, such as 1 cm = 2 N. Draw arrows with a ruler and protractor, then report an estimate to a precision the drawing supports. A calculated component method often gives a more precise magnitude than a hand-drawn diagram, but both should agree within reasonable drawing uncertainty. Significant figures communicate the reliability of measured input; do not report six decimal places from a protractor estimate.
Work it through
A diagram uses 1 cm = 2 N and a resultant arrow measures 4.5 cm. The graphical resultant is about 9.0 N. If an independent component calculation gives 9.2 N, the values are compatible if the diagram uncertainty is around a few millimetres. Explain the difference as measurement uncertainty, not proof that one representation is useless.
Mastery target
Construct and read a scale-vector representation, report an appropriate precision and compare a graphical estimate with a component calculation.
A scale says 1 cm = 2 N. What force does a 4.5 cm arrow represent?
Name the key physics term from Vector graphs, scale and measurement uncertainty that best fits the explanation and visual model.
A vector has perpendicular components 6 N and 8 N. What is its resultant magnitude in N?
Which statement corrects a common misunderstanding in Vector graphs, scale and measurement uncertainty?