M2.2 - Centres of mass

Centre of mass of a discrete mass distribution in one and two dimensions.

Use centre of mass of discrete distributions to connect the rule to the data and decision in the question.

This matters because centre of mass of discrete distributions determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply centre of mass of discrete distributions to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: Centre of mass of discrete distributions is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Centre of mass of uniform plane The use of an axis of symmetry will be acceptable where figures, and simple cases of appropriate.; Use of integration is not required.; Figures may composite plane figures. include the shapes referred to in the formulae book.; Results given in the formulae book may be quoted without proof.

Use centre of mass of uniform plane to connect the rule to the data and decision in the question.

This matters because centre of mass of uniform plane determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply centre of mass of uniform plane to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: Centre of mass of uniform plane is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Simple cases of equilibrium of a The lamina may plane lamina. (i) be suspended from a fixed point; (ii) be free to rotate about a fixed horizontal axis; (iii) be put on an inclined plane.

Use simple cases of equilibrium to connect the rule to the data and decision in the question.

This matters because simple cases of equilibrium determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply simple cases of equilibrium to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: Simple cases of equilibrium is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.