Unit 1 Revision Flashcards
What is the x-component of a force?
F * cosθ
What is the y-component of a force?
F * sinθ
How do you calculate a force’s magnitude from its components?
√x^2 + y^2
How do you calculate a force’s angle from its components?
tan(y/x)
How do you calculate a moment?
M = F x d
What is a moment?
A moment is a turning effect on a body relative to a point, created by a perpendicular force.
What is gravity defined as?
9.8m/s^2
What is the difference between weight and mass?
Mass is how much matter in an object, weight is the force of gravity acting on that mass.
What is Newton’s first law?
An object will remain in its current state of motion unless an external force acts on it. Objects have inertia.
What is Newton’s second law?
F=ma
What is Newton’s third law?
Every action has an equal and opposite reaction.
How do you calculate density?
Divide mass by volume
What is density?
For a substance, how much mass there is within a set volume.
What is Archimedes’ principle?
The size of upthrust is equal to the weight of the water displaced.
What is the formula for upthrust?
Upthrust = density x volume x gravity
How do you find a zero force members?
If a joint has two non-colinear members, and the joint has no load or support reaction, these members are zero force members.
If a joint has two colinear members connected, and another member, then the non-colinear member is a zero force member, if the joint has no load or support reaction.
Why are zero force members included?
To increase stability and rigidity of a truss.
What are four main material classifications?
Metals, Ceramics, Polymers, Composites
Metal Properties?
Malleable, Strong, Conductive
Ceramic Properties?
Hard, Strong, Brittle
Polymer Properites?
Low Density, Can be either flexible or hard, Insulating
What are primary bonds?
Bonds that involve directly bonding between atoms and sharing electrons (ionic, covalent, metallic).
What are secondary bonds?
Weaker bonds that hold together groups of molecules (i.e. van der waals forces)
What are covalent bonds?
Bonds between non-metals. They share electrons between two atoms’ outer shells
