Track 8

Track 08

Lisa: OK, as I understand it, we’ve got to build a device that will allow us to convey a ping-pong ball from one table to another a metre away. Bill, what have we got?

Bill: We’re only allowed to use: six sheets of paper, a box of paper clips, some thread, four drinking straws, and two elastic bands.

Lisa: I’m not sure where to start. Anybody got any ideas?

Omar: Maybe we could use the elastic bands to launch the ball across the gap…

Bill: That’s not a bad idea, Omar, but I think that would be rather difficult to do. Hmmm.J think we should create a sort of bridge with the sheets of paper. We could suspend it between the tables.

Omar: How would that work?

Bill: We could cut the paper into strips of about 10 cm wide…

Lisa: I get it!…and attach them end-to-end with paper clips. But how would we secure the bridge to the table?

Omar: We could use thread for that - I’m sure we could work something out. But what I’m not sure about is how we can keep the ball from falling off the bridge.

Lisa: Well, if we fold the sides of the paper so that it forms a cylinder or tube that would keep the ball from rolling onto the floor. This would also help keep the bridge rigid enough to span the distance between the tables. What do you think Bill?

Bill: I think that’s a brilliant idea. If necessary we could use the drinking straws to further reinforce the structure.

Oma: Do you think 10 cm strips would be wide enough? What’s the diameter of a ping-pong ball?

Lisa: That’s a good question Omar. I don’t know maybe two and a half centimetres - OK what about 15 cm?