Linear/angular motion and fluid mechanics Flashcards
(15 cards)
What is linear motion?
Movement of a body in a straight/curved line where all parts of the body move the same distance in the same direction over the same time
How does linear motion come about/result?
From a direct force being applied to a body
What’s the difference between distance and displacement?
Distance = total length of path covered (start to finish)
Displacement = shortest straight line route from start to finish
What’s the difference between speed and velocity?
Speed is the rate of change of distance whereas velocity is the rate of change of displacement
What is angular motion?
Movement of a body/body part in a circular path about an axis of rotation
What results in angular motion?
Eccentric force (torque) being applied to a body outside the COM
What is moment of inertia?
Resistance of a body to change it’s state of angular motion or rotation
What is angular velocity?
Rate of change in angular displacement or rate of rotation
What is angular momentum?
Quantity of angular momentum possessed by a body
How does mas effect size of moment of inertia?
Greater the mass the greater the moment of inertia
How does mass distribution affect size of moment of inertia?
Further the mass from axis of rotation greater the moment of inertia
Movements where mass is tucked round axis of rotation lower the moment of inertia
How does moment of inertia affect angular velocity?
High = high resistance to rotation, low angular velocity and low spin rate
Low = low resistance to rotation, high angular velocity and fast spin rate
What is conservation of angular momentum?
Conserved quantity which remains constant unless an external eccentric force or torque is applied
What is angular analogue of Newton’s first law of motion?
Angular equivalent of Newton’s 1st law of motion
states a rotating body will continue to turn about axis of rotation with constant angular momentum unless acted upon by eccentric force
What are the 4 factors affecting resistance and drag of a body and how?
Velocity = greater velocity means greater air resistance and drag
Front x sectional area = lower/smaller cross sectional area reduces air resistance
Streamlining = more aerodynamic shape of body and equipment lowers air resistance and drag
Surface characteristics = increased smoothness e.g lycra reduces air resistance
