2.2 instantaneous velocity-2.6 motion on incline plane Flashcards
instantaneous velocity
an object’s speed and direction as its velocity at a single instant of time
instantaneous velocity at time t is the _______(on a position tine graph)
slope of the tangent to the curve at that instant
instantaneous velocity at time t is the _______(on a position tine graph)
slope of the tangent to the curve at that instant
Relationship btwn vaverage and v instantaneous. + formula
The average velocity becomes a better and better approximation to the instantaneous velocity as the time interval (delta t) gets smaller and smaller.
vs=lim (delta t approach zero) Delta s/Delta t
curved position time graph means v is
changing
average acceleration
The slope of the velocity g-vs time graph
An object is slowing down if and only if
Vx and ax have different signs
An object’s final position is (formula with velocity)
sf=si+area under the velocity curve vs between ti and tf.
Graph for p-t v-t of positive constant acceleration
Free fall (2)
The motion of an object moving under the influence of gravity only and no other forces
- 9.81m/s^2 down
when does free fall only occur in?
Occurs only in a vacuum where there is no air resistance.
Model of motion in the absence of air resistance: (2)
- Two objects dropped from the same height will, if air resistance can be neglected, hit the ground at the same time and with the same speed
- Any two objects in free falls regardless of their mass, have the same acceleration.
Despite the name, Free fall is….
not restricted to objects that are literally galling. Any object moving under the influence of gravity only and no other force is in free fall. This includes objects falling straight down or objects tossed or shot straight up and projectile motion.
gravity is
a force not an acceleration
free fall acceleration (3)
The length or magnitude a(freefall)
g=9.80m/s^2
Always positive
