ax = (vxf - vxi)/∆t, where ∆t =
(tf - ti).
vxf = vxi + ax ∆t.
vx(avg) = (vxf + vxi)/2.
xf - xi = vxi∆t + ½ ax∆t2.
vxf2 = vxi2 + 2ax(xf - xi).
vx = v0x, ∆x = v0xt, vy = v0y - gt, y = y0 + v0yt - ½ gt2.
F = -kx
W = F·d ,
The work done by a force can be positive or negative. If the component of the force in the direction of the displacement is positive, the work is positive, and if the component of the force in the direction of the displacement is negative, the work is negative.
Kinetic energy: K = ½mv2.
Gravitational potential energy: Ug = mgh (with ground as reference).
Elastic potential energy: Us = ½ kx2.
P = ∆W/∆t
fs≤ μsN, fk = μkN.
Centripetal acceleration: ac = v2/r.
Centripetal force: Fc = mv2/r.