A grl is strapped to a board that is moving so that gamma along the length of the board is 2.0. The board and direction of relativistic motion is along the horizontal. You are standing next to a hole on a horizontal platform that she hopes to pass through (with the board's length parallel to the platform) when she arrives. The board has length L in her reference frame. The diameter of the hole is 0.75 L in your reference frame. (you can neglect the vertical component of the movement necessary for the pot to pass through the hole.
a) what is the length of her board in your reference frame when it arrives? Does she pass through?
b) what is the diameter of your hole in her reference frame when she arrives? Can she pass through?
c) Given that you've witnessed her passing through the hole, she must have passed through in her reference frame as well.