PSA Microgravity Challenge
Caroline Robins Community School, Canada
Mrs. Liebrecht’s Grade 4/5 class
By: Rochelle, Chelsea, Nicole and Jenna
Our PSA: We built our PSA out of two
pieces of cardboard, a tennis ball, two pieces of string and one remote
controlled mini skateboard.
How our PSA works: We cut out and taped
two pieces of cardboard and stuck them on to opposite ends of the
remote controlled skateboard. Then we stuck two strings into the tennis
ball and tied the two ends through the pieces of the cardboard. With
the remaining piece of string, we held the end of the string and let
it go. This caused the tennis ball to lift up 3 inches. We can easily
move the PSA forward and back by the use of the remote controlled
Response from Expert Dan Andrews - (See Final
Design for Student Responses):
This is a very nice diagram, and I think I
sort-of understand how it works. If I push on the PSA (ball) the skateboard
will begin moving.
What if I push the PSA sideways, though? I
don't think the skateboard could move in that direction, so the PSA couldn't
What if I pulled-up on the PSA (Ball)? Would
it keep moving up, or would it fall back down as soon as I let go of it?