Purpose: The activity will help give students
a kinesthetic feel for the inertia concept. This lab is a great
way to provide students with an experience that can be very thoroughly
discussed and analyzed.
Materials:
- one bowling ball (the heavier the better),
- many two-liter bottles half filled with water and
capped tightly for route markers
- one broom
- stopwatches
- masking tape to mark no touch zone, start/stop, and
possibly the route itself
Procedure: Create a course like the one pictured
above using the bottles as route markers. Students are to navigate
a bowling ball through obstacle course as quickly as possible,
steering the ball with only a broom. Timing the students encourages
them to go as quickly as possible, and it also makes the tendency
of a 14-pound bowling ball to stay in motion more noticeable.
The ball starts at rest and the run begins on the mark of the
timer. The timer stops the stopwatch when the student brings the
ball to rest in the stop circle. A five second penalty is added
for each bottle knocked over.
Variation: Set up two identical courses and
have students race in pairs, or run the race as a relay.
Once students have completed the race, they should
answer the questions on the Student
question sheet
Lab performance notes: The no-touch zone gives
students a chance to see the ball in motion with no net force
on the ball. Sharp turns help students to see that in addition
to pushing the ball to give it motion in a new direction, the
motion in the original direction must be stopped. Circling a globe
or other round object provides and experience from which to talk
about circular motion.
Take time to discuss each question thoroughly. Answered student question sheet and
points for discussion
If time permits, you may run the races again after
the students have discussed the activity to see if they can improve
their times by applying what they have learned.