Physics and Pennies

Have you ever thought of how you can cheat in a Penny Knuckle game? Well the answer is simple. It’s PHYSICS- the kinematic motion of an object. You don’t have to cheat. You can win fairly by using a mathematical equation! Using equations gives you an accurate answer each time. 

First, measure the length of the surface you are going to push the penny on, such as a table.  Next, acquire a penny and a stopwatch. Place the penny on the end of the table and find an object that can get the penny to travel from one end of the table to the other, such as a textbook. Using your stopwatch, measure the amount of time it takes for the penny to travel across the table. Record your results.

Initial Velocity of a Penny Lab

Vf= 0 m/s        D= 1.835 m      T= 1.08 s

D= ½ (Vf + Vi) x t

1.835= ½ (0 + Vi) x 1.08

1.835/1.08= ½ Vi

1.694= ½ Vi

3.39 m/s = Vi

The motion of the textbook pushing the penny (the textbook’s initial velocity), must be the same each time, in order to get accurate results. Since we knew that the distance of the table was 1.835 meters, the final velocity of the penny was 0 m/s and the time it took for the penny to travel from one end of the table to the other end was 1.08 seconds, we used these measurements and plugged them into the equation (D= ½ (Vf + Vi) x t) to find the initial velocity needed to push the penny across the table, which was 3.39 m/s.


Wasn't that easy?