We can predict that if you let go of the block, it's probably not going to move down the hill as fast as the ball, if it moves at all. You know that round things roll, and things with edges generally don't. Even though physics governs the actions of the two objects, you don't have to have a physics background to make the guess, you just know. How do you know? Because as a kid, you probably played with blocks and balls and ramps. All your experiences helped you make that prediction in a split second.