Statics: Why Bridges Are Built From Triangles
The hidden balancing act behind everything that stands still, from picture wires and seesaws to trusses, I-beams and friction.
Statics · 50 questions
Try 3 questions
1. Two 10-newton forces pull on a ring at right angles to each other. About how large is their resultant?
- About 14 newtons
- About 10 newtons
- Exactly 20 newtons
Show the answer
Answer: About 14 newtons
Perpendicular forces add like the sides of a right triangle: √(10² + 10²) ≈ 14 N.
2. Two 10-newton forces act on a point with 120 degrees between them. What is the size of their resultant?
- About 17 newtons
- Exactly 20 newtons
- Exactly 10 newtons
Show the answer
Answer: Exactly 10 newtons
The resultant is 2 × 10 × cos 60° = 10 N, the same size as each force; at 120° the pair forms an equilateral triangle.
3. Must a force always be broken into perpendicular components, such as horizontal and vertical?
- No, any two non-parallel directions work
- Yes, only right angles give valid parts
- Yes, unless the force is already vertical
Show the answer
Answer: No, any two non-parallel directions work
The parallelogram law lets you resolve a force along any two non-parallel lines, which is handy for inclined members.
The whole quiz comes before your apps
BrainTok asks a few questions like these before the apps you choose open, so your screen time turns into learning. For iPhone.
Join the beta