Useful Formulae and Constants
Dot Product
A B Ax Bx Ay B y Az Bz
Rotational Kinematics
1rev 2 rad 360
,
t
t
Cross Product
A B ( Ay Bz Az By )iˆ
s r, v r , a r
( Az Bx Ax Bz ) ˆj
( Ax B y Ay Bx )kˆ
f
1
T 2
0 t
1
0 0 t t 2
2
2 20 2 0
Work, Energy, and Power
W F d Fd cos
1
KE mv 2
2
PE grav mgh (near surface)
Mm
(planetary)
R
1
PEelastic kx 2
2
WNC KE PE
Energy E
P
F v
Time
t
PEgrav G
Rotational Dynamics
Torque: r F
magnitude: rF sin
direction: right-hand rule
2
I mi ri , I r 2 dm
1 2
I (fixed axis)
2
1 2 1
KE mvcm
I cm 2 (moving axis)
2
2
Angular momentum: L r p, L I
KE
Momentum and Impulse
p mv
J p Ft Fdt
Conservation of Momentum
m1 v1 m2 v 2 m1 v1 ' m2 v 2 '
I
1-Dimensional Elastic Collision
P
v1 v2 v1 ' v2 '
2