L3 Mechanics Flashcards
Define:
Freefall
Motion under one force - gravity.
Define:
Impulse
Change in momentum by an external force.
Compare:
Elastic vs Inelastic
Collisions
Elastic: where kinetic energy is conserved
Inelastic: where kinetic energy is not conserved (due to sound or heat)
Define:
Inertia
The property of matter that causes it to resist change to its motion (or lack of).
Explain:
Newton’s 1st Law of Motion
A body continues in a state of rest or uniform motion in a straight line unless acted upon by an external force.
Explain:
Newton’s 2nd Law of Motion
The force acting on a body is equal to the product of its mass and acceleration.
Explain:
Newton’s 3rd Law of Motion
To every action there is an equal and opposite reaction.
Define:
Resonant Frequency
The vibration frequency of an elastic object that depends on size, composition, and shape of the object.
Define:
Restoring Force
The force which moves an oscillating object back towards equilibrium.
Define:
Rotational Inertia
The measure of the reluctance of an object to change its rotation.
Define:
Simple Harmonic Motion
The vibratory motion of an object when there is a restoring force that is equal an opposite to a displacement.
Define:
Law of Conservation of the Centre of Mass
the centre of mass of an object remains at rest or at a constant object, unless an external force acts on a system.
Define:
Conservation of Momentum
If a closed system is not affected by external forces, its total linear momentum does not change. Momentum is conserved in a collision.
Explain how to find the velocity required for circular motion of:
Banked Tracks
(Banking Aircraft, Conical Pendulums)
- equating centripetal and weight force
Rsinθ = mv^2/r Rcosθ = mg
Rsinθ/Rcosθ = (mv^2/r)/mg
tanθ = v^2/rg
v = √rgtanθ
Define:
Newton’s Law of Gravitation
Every mass attracts every other mass.
