A rockbreaker breaks into the Tanuk arena, throwing up boulders and logs on the way in so the rebels can attack (at high speeds too). The average height of a person is 1.7m.
111 pixels = 1.7m
1 pixel = 1.7m/111 = 0.0153153153m
0.0153153153m X 546 = 8.36216215m
8.36216215m/2 = 4.18108107m...