Forces

Applied Mathematics — Second Secondary

Common mistakes

Comparison aspect	Main idea	Example	Keywords
Mistake	confusing mass with weight	saying that the weight of a body is 5 kg. Correct: mass is measured in kilograms and weight is measured in newtons	confusingmassweightexample
Mistake	writing a magnitude as negative	force = −20 N. Correct: the magnitude is always positive a negative sign only shows that the direction is opposite to the one chosen as positive	writingmagnitudenegativeexample
Mistake	leaving out the direction in the answer. Correct: a force is not fully described until its direction is stated	—	leavingdirectionanswerCorrect
Mistake	forgetting that weight acts vertically downwards even when the body is on an inclined plane. Correct: always draw the weight as a vertical arrow pointing down	—	forgettingweightactsvertically

Forces · 5 / 6