Forces, Moments & Stress is one of 9 topics in the Grade 12 Mechanical Technology CAPS syllabus, covered across 3 lessons on Study Vault. Below are real practice questions from this topic with full worked answers.
Sample practice questions
Easy
1. What is the resultant of a system of forces?
The single force that has exactly the same effect as all the individual forces acting together
A force that is always zero
The average of all the individual forces' magnitudes
The force with the smallest magnitude in the system
Answer: The single force that has exactly the same effect as all the individual forces acting together — The resultant is the single force that produces exactly the same net effect as all the individual forces in a system acting together.
Easy
2. How does the equilibrant of a system of forces relate to the resultant?
Same magnitude, opposite direction (180 degrees rotated)
Same magnitude and same direction
Always exactly double the resultant's magnitude
Always zero, regardless of the resultant
Answer: Same magnitude, opposite direction (180 degrees rotated) — The equilibrant has exactly the same magnitude as the resultant but acts in exactly the opposite direction, since it is the force needed to bring the system into equilibrium.
Medium
3. Name the mathematical theorem used to combine total horizontal and total vertical force components into the resultant's magnitude.
Answer: Pythagoras — Pythagoras' theorem combines the total horizontal and vertical components (as the two shorter sides of a right triangle) to find the resultant's magnitude (the hypotenuse).
