To enable motion blur for Element turn on the layer switch for motion blur and then toggle the motion blur switch on the timeline. The motion blur samples will smooth out fast motion but take longer to render.
Control whether the motion blur is turned on by the Comp Settings, On, or Off.
Turn up the samples to smooth out motion blur for fast motions. Higher samples will take longer to render.
ADDING MOTION BLUR TO BAKED OBJ SEQUENCE
If you are using an obj sequence, between obj animation file frames there is no real motion. Camera animation can give some motion blur to the obj sequence, but for natural looking motion blur there are a few different methods. One way would be to pre-render your animation as a video file, add the effect CC Force Motion Blur, and turn on Frame Blending for the comp and layer. Another effect is Timewarp, set the speed to 100 and enable the Motion Blur switch. There is also a 3rd party plugin called Real Smart Motion Blur that creates motion blur by interpolating between the frames.