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Page 10
Newton's Laws Stations Activity
Coin Catch (student handout)
Overview:
This Coin Catching Trick walks a fine line between Illusion and Science. This
trick may take some timing to perfect but it is sure to wow family and friends.
The object is to rest a coin on your elbow and snap your arm forward and catch
it. The trick is that you will be catching the coin with the same hand as the
elbow on which the coin rested.
This experiment is based on the science of inertia. Since the coin is at rest, it
tends to remain at rest, so when your elbow moves quickly it literally just drops
out from underneath the coin, leaving the coin in mid air for a moment. Gravity
still pulls the coin down but inertia is what gives the coin a very slow start be-
fore dropping. Your hand is faster than the coin in this situation because your
hand is already in motion and stays in motion.
Materials:
• Coin(s)
Step-by-Step Procedure:
Practice this first to determine how many quarters you are comfortable using.
1. Bend your elbow and place your hand at your ear, so that your forearm is perpendicular to your face.
2. Stack the quarter(s) on the flat portion of your elbow.
3. Throw your arm forward slowly and try to catch the coins with the same hand.
4. Repeat, this time moving your arm quickly enough to catch the coins.
5. Compare the results from the slow and fast trial.
Test Your Understanding:
Explain how Newton's laws are involved in this activity. Use complete sentences.
Name: Class: Date:
