Newton's First Law in a Car
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Demonstrates the First Law in accelerating, decelerating, and
turning cars. Demonstrates the purpose of seat belts.
"Super Dave" figure
concrete block (for collision)
2 rubber bands
wooden block (for seat back)
- Place the figure on the bare dynamics cart. When car
accelerates from rest, show that you remain at rest while car
accelerates. Add a seat (wooden block held with a rubber band) to
show that seat provides the force to accelerate the person.
- Crash the cart into the barrier. Show that the person
continues to move at the same velocity when the car stops (They
aren't "thrown forward.") Add a seatbelt (rubber band) to show
that the seatbelt supplies the force to stop you.
- Take person out of the seatbelt. Show that as the car turns,
the person continues to go straight. (There is no "centrifugal
As above. See also Riding in a Car
and Thoughts on Force and Newton's
adapted from Robinson, Conceptual Physics Laboratory
Manual, Addison-Wesley, Activity 8 - Buckle Up!
last update November 16, 2009 by JL