Structures
An anthill is an example of a _____ structure.
Natural
A force is a push or a _____ .
pull
All structures have at least one _________ and a form.
function / purpose
Gravity and magnetic force are examples of _____ forces.
non-contact
_____ is the point around which a structure’s mass is equally balanced in all directions.
Centre of gravity
A beam is a _____ structure designed to support a load.
horizontal
_____ is the shape and physical appearance of a structure.
Form
If an astronaut has a weight of 900 N downward on Earth, how much would he weigh on the Moon?
150 newtons (N)
An object will _____ if its centre of gravity passes outside its base.
topple over
The cardboard boxes are strengthened by the use of _____ in them.
corrugation
Sponge is an example of a _____ (solid / shell / frame) structure.
Solid
Name the four internal forces we learned.
1. Tension 2. Compression 3. Torsion 4. Shear
Why do tightrope walkers carry a long downward curving pole that is heavy at both ends?
To lower the acrobat's centre of gravity.
A _____ is a beam that is supported at only one end.
cantilever
The frame of the CN Tower supports the metal skin, which act as a shell. Therefore, the CN Tower is a _____ structure.
Combination
Identify at least one example of a dead load, live load, and dynamic load that might act on a bridge over a river.
Dead load: The weight of the structure (the bridge)
Live load: cars, people
Dynamic load: rushing water, wind, etc.
Why is a sports car more stable than a truck? Explain by giving two reasons.
1. It has a lower centre of gravity.
2. It has a wide support base.
A _____ is similar to a tie, but it is placed below a beam where it provides resistance to the forces of compression.
strut