Question

multiple - choice question
tangential/linear velocity is ________. (check all that apply.)
perpendicular with the radius of circle.
parallel to the surface.
tangent to the circle.

Explanation:

Tangential/linear velocity is perpendicular to the radius of the circle (since the radius is from the center to a point on the circle and the tangent at that point is perpendicular to it). Also, for an object moving in a circular path (like a wheel), the tangential velocity is tangent to the circle. If we consider a wheel on a surface (assuming it's rolling without slipping), the direction of the tangential velocity at the point of contact with the surface is parallel to the surface (opposite to the translational velocity direction in some cases, but still parallel).

Answer:

perpendicular with the radius of circle, parallel to the surface, tangent to the circle