“What effect does mass have on the inertia of an object?”
Problem: You are given an index card, a glass jar, and three
objects that have different masses (low, medium, high). You will
place an object on top of the glass jar and “flick” the card sideways.
Will the object land in the jar or fly sideways with the index card?
Will the mass of the object have an effect on how many times the
object will land in the jar?
Background Information: An object resting on the card is at rest. All matter has inertia, the tendency of all matter to resist any change in motion. According to Newton’s first law the object will remain at rest unless an unbalanced force acts upon it. You will exert an unbalanced force upon the index card. Will this force be great enough to overcome the inertia of the object as well? You must flick the card quickly to overcome the friction between the card and the object if the
object has any chance of remaining at rest and falling in the jar.
(1) Place index card (long ways) over the mouth of the jar and place the low
mass object on top.
(2) With your index finger or middle finger and thumb "flick" the card and
record whether the object falls in the jar or misses the jar. (3) Repeat 5 times with the low mass object then your partner will try 5 times
with the low mass object for a total of 10 trials all together. (4) Switch to the medium mass object and repeat. You will attempt 5 times and
your partner will attempt 5 times. Always record the number of times it falls in
or misses the jar.
(5) Repeat procedure with the large mass object.
(6) Write your final data on the board. Record the number of times the high,
medium, and low mass object fell in the jar.
(7) Calculate a class average for the high, medium and low mass objects and
record in the class average column.
Mass # of Times Object # of Times Object CLASS
Misses Jar Falls in Jar AVERAGE
INERTIA ACTIVITY CONCLUSION QUESTIONS
1. What is inertia? Explain why it is the inertia of the object that causes it to
fall in the jar.
2. Why was it necessary to “flick” the card instead of pull it out slowly?
3. According to the class data chart which mass object fell in the jar the most
often? Explain why by discussing the relationship between mass and
4. Did the data you and partner collected show the same results as the class
data. If not can you explain the difference?