Crushing Cans Lab
Question: How does changing the height of the Crush-o-Matic bucket affect the amount that the
cans are compacted (crushed)?
Background Info: Gravitational potential energy comes from the position of an object. When an
object being held above the ground is released, its gravitational P.E. is converted to kinetic
energy as it falls towards the ground.
Independent Variable (What “I change”): Height of the bucket
Dependent Variable (What is being measured): Height of the crushed can
Constants (never change): Weight inside the bucket, starting height of can, type of can
Control (“Normal”): Uncrushed can
Hypothesis: If we increase the height of the bucket, then the cans’ crushed height will
___________ because ____________________.
Materials: Crush-o-Matic, empty soda cans, meter sticks/rulers, lab notebook, graph paper
Safety considerations: GOGGLES MUST BE WORN BY ALL STUDENTS WITHIN THE
“CRUSH-O-MATIC ZONE.” Be sure all students are clear of the bucket before it is released.
Be careful when handling the crushed cans, they may have sharp edges!
Procedures:
1. Set up the Crush-O-Matic (ladder, bucket, string, cardboard to protect floor) inside the “Crush
Zone”
2. Working in groups of 2 students:
Student A raises bucket to designated height.
Student B places can under bucket, and calls “clear” once their hands/feet are clear from
the drop zone.
Student A announces “Fire in the Hole” and releases string to drop the bucket
Student B removes can.
3. Reverse roles so each student gets to set up can and drop the bucket.
4. When finished crushing cans, students return to seat to measure the final height of their cans.
5. Record can height in data table on document camera.
6. Record data from other groups as they complete steps 2-4.
Diagram: Draw a diagram of the Crush-o-Matic and label the parts.
Data Table:
Height of Bucket
Trial 1
Trial 2
Trial 3
Trial 4
Trial 5
Trial 6
Trial 7
Average
Graph:
Make a bar graph of the average crushed height of the can (dependent variable) for each bucket
height (independent variable).
Bucket Height 1
Bucket Height 2
Bucket Height 3