# Physics chapter 2 and Lab

version from 2015-09-21 03:47

## Section

distancetotal length of travel, from beginning to end, always positive
displacementthe change of position, xf-xi (final position minus initial position)
positive and negative displacementsign of displacement indicates the direction of motion (>0 is to the right, <0 is to the left)
units- distancemeter, (m)
average speeddistance divided by elapsed time, (av= distance/time)
average velocitydisplacement divided by time
graphical interpretation of velocityin an x-versus-t plot, the average velocity is the slope of a line connecting two points
units- speed and velocitymeters per second, m/s
instantaneous velocityvelocity at an instant of time is the limit of the average velocity over shorter and shorter time intervals
constant velocitythe instantaneous velocity is equal to the average velocity
graphical interpretation instantaneous velocityx-versus-t plot, the instantaneous velocity at a given time is equal to the slope of the tangent line at that time
average accelerationchange in velocity divided by the change in time, (vf>vi=+) (vf
instantaneous accelerationlimit of the average acceleration as the time interval goes to zero
constant accelerationinstantaneous acceleration is equal to the average acceleration
decelerationobject whose speed is decreasing, when velocity and acceleration have opposite signs
graphical interpretation accelerationv-versus-t plot, the instantaneous acceleration is equal to the slope of the tangent line at a given time
units-accelerationmeters per second per second, m/s*2
velocity as a function of timev=v0+at
initial,final, and average velocityvav=1/2(v0+v)
position as a function of time and velocityx=x0+1/2(v0+v)*t
position as a function of time and accelerationx-x0+v0t+1/2at*2
velocity as a function of positionv*2=v0*2+2a(x-x0)=v0*2+2a_x (_ is displacment)