Kinematics in One Dimension
Displacement: x  x  x0
Average velocity: vave 
Average speed =
x x  x0

t
t  t0
Average acceleration: aave 
v v  v0

t
t  t0
total distance
elapsed time
Instantaneous velocity: v  lim
t  0
Instantaneous acceleration: a  lim
 An object speeds up if the velocity and acceleration point in the same direction;
it slows down if the velocity and acceleration point in opposite directions
Equations of Constant Acceleration:
v  v0  at
1
(v0  v )t
2
1
x  x0  v0t  at 2
2
2
2
v  v0  2a ( x  x0 )
x  x0 
freefall: gravity is the only force acting on an object (no air resistance)
Equations of Freefall:
v  v0  at
1
(v0  v )t
2
1
y  y0  v0t  at 2
2
2
2
v  v0  2a ( y  y0 )
y  y0 
Notes for Freefall:
 a = 9.8 m/s2 downward or a = –9.8 m/s2 if up is defined as +
 v = 0 m/s at the highest point
 freefall motion is symmetric
x
t
t  0
v
t