Rigid Body Kinematics Flashcards
What are the characteristics of a particle?
Negligible dimensions, negligible rotation, assumed to be a point
What is particle kinematics?
Discipline of mechanics that deals with motion of a particle over time WITHOUT ref. to the forces that cause displacement, v, and a
What is a scalar quantity?
Defined only by magnitude.
What is a vector quantity?
Has magnitude and direction.
What are the vector quantities for distance, mass and speed?
Displacement, weight and velocity
What is particle plane motion?
Moving in a plane/2D
What are the types of particle plane motion?
Rectilinear and curvilinear
Displacement is…
Amount of change in position
If displacement is not 0 the particle is…
Moving
Speed of the particle depends on…
The time it took to move
What is the rate of change of the position of the particle
V= delta x/ delta t ( change in position/change in time)
What do you call the magnitude of velocity?
Speed
If the velocity of an object is changing the object is …
Accelerating
Constant velocity means…
Speed and direction do not change
The rate of change of velocity is called…
Acceleration
Aristotle thought that…
All motion on Earth is linear. Diff. Masses fall at diff. Rates. Natural stat of massive objects is to seek the center of the Earth. All motion in the heavens is curved.
According to Aristotle what is natural motion? Violent?
Motion is at rest or constant speed. Violent is otherwise.
Galileo discovered that…
Diff. Masses fall at the same time. Friction prevents this from happening when not in a vacuum.
What are Newton’s laws of motion?
Inertia, Acceleration, Action-reaction
Projectile motion is…
Not purely curvilinear. Only force acting on the particle is gravity. Thrown things. Can be resolved into horizontal and vertical forces.
What angle is max range? Max elevation?
45, 90
What is uniform circular motion?
Constant speed along a circle
What is the formula?
Average speed = 2pi r/t
In circular motion velocity is…
Always changing.
Tangential velocity is…
Velocity along a circular path
2 types of speed?
Average speed and instantaneous speed.
What is acceleration?
Rate of change of velocity with respect to time.
The velocity change vector is directed towards…
The center
What is normal acceleration?
Acceleration directed inwards
What is the formula for normal acceleration?
An=v^2 /r where v is the tangential velocity
If the magnitude of v changes, there is…
Tangential acceleration
What is centripetal force?
Center seeking force; direction of net force is that of acceleration
Centripetal force for uniform circular motion alters…
Direction without altering speed
The presence of _______ is required for objects to move in a circle.
Unbalanced force
What are the requirements for centripetal force?
Friction, force of tension, force of gravity
What is the study of how things move without looking into the causes?
Kinematics
What is a rigid body?
Dimensions and rotation are NOT neglected; deformation is.
Do rigid bodies actually exist?
No but if deformations are small relative to motion we could treat the object as one.
What are the types of plane motion?
Translation, centroidal rotation, general plane motion
2 points will have diff. Tangential velocities dependent on…
Rate of rotation and distance from CM
What is Kinetics?
Study of relationship between motion of objects AND ITS CAUSES.
What is Newton’s 2nd law of motion?
F=ma where f is your net force and ma is the inertial force
If v is perpendicular to f the direction of v will…
Change
What is dynamic equilibrium?
When an object is accelerating. Motion is not necessarily 0
Static equilibrium is when…
Acceleration is 0
In dynamic equilibrium…
Acceleration is not 0, net force is not 0 ( it’s moving)— freeeee fall!
What is terminal velocity?
Constant velocity at which object is moving due to the restraining force exerted by air.
What is weightlessness?
A sensation caused by not being in contact with external objects which would usually exert a push or pull
