THE TURNING EFFECT OF FORCES
2 marks · NormalState what is meant by the 'centre of gravity' of a body, and describe how the weight of a body acts with respect to this point.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
The centre of gravity is the point where the whole weight of a body appears to act; the weight acts vertically downwards through this point.
Also accept: The point through which the entire weight of the body acts.; The centre of mass where gravity acts.
Common mistakes: Saying 'the middle' without reference to weight; Not mentioning the direction of the weight
Show mark scheme and worked solution
Marking points
B1 · 1 mark · Correct definition of centre of gravity.
B2 · 1 mark · States that the weight acts through the centre of gravity.
Worked solution
The centre of gravity is the point in a body where the whole weight appears to act. The weight acts vertically downwards through this point.