The path of a point is described by the equation R = (t 2 +4)ejt/10, where R

The path of a point is described by the equation R = (t 2 +4)e−jπt/10, where R is in millimeters and t is in seconds. Find the unit tangent vector to the path, the normal and tangential components of the absolute acceleration, and the radius of curvature of the path, at t = 20 s.