previous    next
Rotation


The acceleration vector a is at each instant of time t given by the time derivative of the velocity vector v.

a(t) = dv(t)/dt = (
dvx(t)/dt
dvy(t)/dt
) = (
2R cos(ωt)
2R sin(ωt)
)

since
dvx(t)/dt = d( -ωR sin(ωt) )/dt = -ω2R cos(ωt)

and
dvy(t)/dt = d( ωR cos(ωt) )/dt = -ω2R sin(ωt)

The resulting acceleration vector is indicated in the above video. Notice that a and v are perpendicular and, consequently, that a and r are parallel.


next