we have a science project and we need to make a pneumatic can crusher (grade 8)?
Do you have a compressed air tank? Or maybe I should ask what the parameters are of the assignment.
You need a bunsen burner, a pair of tongs and a sink full of cold water close to the bunsen. Take a can in the tongs and (carefully) hold it VERTICALLY with the open end over the bunsen flame until really hot. Keeping the hot can with open end down, QUICKLY immerse the open end into the cold water (not deep), without tilting it. There'll be a fairly loud (but safe) 'bang' and, the can will completely collapse due to a high vacuum created in the can. The pressure difference between the atmosphere acting on the large surface area of the can, and the vacuum in the can will provide you with a 'Pneumatic Can Crusher'.
