A spring whose spring constant is 850 N/m is compressed 0.40 m.  What is the maximum speed it can give to a 500. g ball? 4.    If the spring in #3 were compressed twice as much, how many times greater would the velocity of the ball be?

i guess that visual aids present persuasive examples to what you are presenting, some factors would be theme (does it fit with the color, information, what you are presenting), size (can you see it, is it a big enough span of data/information), and overall look of the visual aid.

hope this : )