Definitions
Timestep – the time increment at which a rock path calculation is performed; a trajectory results from calculations at numerous timesteps.
Bounce height – calculated as the z-position of the rock minus the z-position of the slope directly beneath.
Impact height – calculated as the distance along a barrier from the rock impact point to the barrier base.
Impact angle – calculated with respect to the normal of a barrier; an impact angle of 0 means the rock is impacting normal to the barrier; a positive impact angle results from a rock travelling towards the base of a barrier; a negative impact angle results from a rock travelling towards the top of a barrier.
Height over barrier – the absolute vertical distance between the rock and the top of the barrier.
Total kinetic energy – the sum of the translational and rotational kinetic energies of a rock.
Translational kinetic energy – the kinetic energy of a rock as it is moving with a translational velocity (= ½ mv2, where m = mass, v = translational velocity).
Rotational kinetic energy – the kinetic energy of a rock as it is moving with a rotational velocity (= ½Iω2, where I = moment of inertia, ω = rotational velocity).
End Point – the location at which a rock path comes to a stop.
Impact Point – a location where a rock is in contact with the slope.
Runout Distance (XY) – the distance between the ending and starting points of a rock path calculated using only the (x, y) values and not the z (i.e., runout distance in the plan view).
Runout Distance (Z) – the distance between the ending and starting points of a rock path calculated using the z-value (i.e., change in elevation).
Runout Distance (Total) – the total distance between the ending and starting points of a rock path considering all changes in the x, y, and z values.
X Vel – translational velocity in the x-direction.
Y Vel – translational velocity in the y-direction.
Z Vel – translational velocity in the z-direction.
X Omega – rotational velocity about the x-axis, positive using the right-hand rule.
Y Omega – rotational velocity about the y-axis, positive using the right-hand rule.
Z Omega – rotational velocity about the z-axis, positive using the right-hand rule.