Structures and Forces: Further Practice
Dead load vs. live load, arches, safety factor, centre of gravity, and bracing.
8 questions, free, marked as you go with a worked explanation on every one.
What this covers
- structures and forces
The questions
- A loaded bookshelf carries the weight of the books placed on it, separate from the shelf's own weight. What is the shelf's own weight called?
- An arch bridge made of stone blocks holds together because each block mainly experiences which kind of internal force?
- A support beam has a breaking load of 60000 N and is used under a working load of 12000 N. What is its safety factor?
- A tall tower and a short tower have the same mass and the same base width. Which is more likely to topple over in a strong wind, and why?
- Use the table below, showing how far four beams of different shapes sagged under the same 500 N test load. Which beam shape is the stiffest?
- A column has a cross-sectional area of 0.02 square metres and must safely carry a load of 8000 newtons. What is the stress on the column, in newtons per square metre?
- A tall bookshelf wobbles side to side. Adding a diagonal brace from one top corner to the opposite bottom corner stops the wobble. Which best explains why?
- A footbridge must carry its own 1200 kg deck plus up to 18 people averaging 65 kg each. What is the total load the supports must carry, in kilograms?