Which type of mass movement happens very slowly?

The type of mass movement that happens very slowly is Creep.

Explanation:

Mass movement, usually known as mass wasting, is that the descent movement of a mass of surface materials, like soil, rock or mud. This mass movement generally happens on hillsides and mountains because of the influence of gravity and may happen terribly slowly or terribly quickly.

the tires are rotating at 0.434 rpmlinear speed=45 m/sdiameter=0.550 mradius=0.275 mnow v= rωω= v/rω=45/0.275ω=163.6 rad/sω=163.6 rad/s (1rev/2π rad) (60s/1m)ω=1563 rpm