Quest: Understanding Gravitational Potential Energy ***
Learning Target:
-I can explain that gravitational potential energy changes in a system as the masses or
relative position(s) of objects are changed.
-I can identify and compare gravitational, elastic, chemical, electrical, and magnetic
potential energy.
-I can, given specific materials, plan and implement an experiment to determine the
relationship between the height/mass of a metal sphere and the amount of change it can
make to sand held in a container below.
The steam-powered robot crashes into a
nearby train station as you deliver the crippling
assault! You manage to secure Necrift at last
and tie his hands together with rope.
“You’ve stopped nothing!” Necrift rages.
“General Ohm will unleash the stored potential
energy in all things! Why do you think we have
wasted so much time capturing scientists?!”
“What potential energy?” you question.
“There exist many types of energy and many
of them are ‘stored’, waiting to be unleashed. I
will give you a hint about the first type of
potential energy. Look to the skies!” The
masked madman nudges his head behind you
where a fleet of enemy airships open bomb
doors. The tiny weapons begin falling over the
city. Each one sprouts a blossom of smoke and
fire! “Gravitational potential energy is working
against you, allowing these weapons to be
pulled by gravity to the streets!”
In the distance you see that a carnival complete with a roller coaster is hammered
hard by the falling explosives. Many of the weapons, however, are causing damage and
destruction even though they are not blowing up.
“All it takes sometimes is a good amount of gravitational potential energy to
cause destruction!” Necrift crows happily! “Not all of them have to explode for them to
do their dirty work. Just think about meteors! The extinction of hundreds of species on
your home of Earth was caused because gravity pulled a hunk of rock into the surface!”
You call out to Da Vinci and the Wright Brothers, “Is the Inertia able to fly yet?”
“Not yet. They are still working on her.” Da Vinci answers. “Hurry to Nikola
Tesla. Help him use his inventions to take out the enemy fleet. I will interrogate our
masked friend here.”
Da Vinci hands you a map and you and your friends rush closer to the carnival
that looks like Coney Island to search for the mysterious Nikola Tesla.
Objective: In this activity, you will be changing the height of a small sphere and the
mass of the sphere to determine their relationship with gravitational potential energy.
You will determine what affects the strength of gravitational potential energy, (GPE).
Quest: Understanding Gravitational Potential Energy ***
Goal 1: Collect data to determine how increasing the height between an object and
the surface affects its GPE
Goal 2: Collect data to determine how increasing the mass of a falling object affects
its GPE
Materials: Steel Ball, Glass Ball, Ruler, Sand
Data Tables- NOTE: USE THE INCLUDED DATA SET AT THE END TO FILL
OUT YOUR DATA TABLES!
Title: Changing the Height of the Steel Ball (Mass of 14 g)
Drop Height
(cm)
Crater
Diameter Trial
1 (cm)
Crater
Diameter Trial
2 (cm)
Crater
Diameter Trial
3 (cm)
Crater
Diameter
Average (cm)
10 cm
25 cm
50 cm
Title: Changing the Height of the Glass Ball (Mass of 5 g)
Drop Height
(cm)
Crater
Diameter Trial
1 (cm)
Crater
Diameter Trial
2 (cm)
Crater
Diameter Trial
3 (cm)
Crater
Diameter
Average (cm)
10 cm
25 cm
50 cm
Quest: Understanding Gravitational Potential Energy ***
Analysis: The strength of the gravitational potential energy is seen in the size of the
impact crater. The larger the crater, the more energy the sphere had to begin with due to
gravity. Use your data from the trials to answer the following in complete sentences.
1. How does increasing the height before impact affect the amount of gravitational
potential energy?
2. How does increasing the mass of the impacting object affect the amount of
gravitational potential energy? For this question, compare the steel ball and marble at the
same height and determine which had a more significant impact crater.
3. Could the strength of gravity between objects have an influence on the amount of
gravitational potential energy as well? (Think of what things can change the strength of a
gravitational field force)
4. One student claims the following regarding how mass, height, and the acceleration due
to gravity are related to gravitational potential energy. He states that as mass increased,
GPE increased. He states that as height increased, GPE increased. He states that as the
strength of gravity increases, GPE would increase. He then writes a formula based on
these relationships: GPE = (mass) x (height) x (acceleration from gravity)
Does your data support his claims? Why or why not?
Quest: Understanding Gravitational Potential Energy ***
5. Calculate the gravitational potential energy, in Joules (J), for the glass ball using the
equation:
GPE = m*g*h Note: We will be calculating this based on the 50 cm drop.
g = 9.8 m/s2
-You must convert the mass of the ball to kilograms.
-You must convert the height of the drop to meters.
Show your work here and circle your answer with proper units.
6. 5. Calculate the gravitational potential energy, in Joules (J), for the steel ball using the
equation:
GPE = m*g*h Note: We will be calculating this based on the 50 cm drop.
g = 9.8 m/s2
-You must convert the mass of the ball to kilograms.
-You must convert the height of the drop to meters.
Show your work here and circle your answer with proper units.
7. Do your calculations of gravitational potential energy for the glass ball and steel ball
match your impact crater size data? Explain using your 50 cm drop height impact crater
data as evidence.
Quest: Understanding Gravitational Potential Energy ***
DATA SET- Use this data that your teacher collected to complete your data tables and
analysis questions.
The data was collected by dropping a glass ball and steel
ball from the stated height (10 cm, 25 cm, and 50 cm)
above a sandy surface. Each ball was dropped for three
trials. The crater that was left by the impact was
photographed beside a ruler. Use the ruler to measure
the crater diameter in centimeters. I have provided a
white circle to indicate the highest ridge for each crater.
This will help you measure to the nearest tenth for your
crater diameter measurements.
Record these crater diameters in the proper location of
your data tables. You will then calculate the average
crater diameter for each height drop trial.
This is a nice introduction to gravitational potential
energy because the crater that is left behind is created by
the energy that the glass ball and steel ball had gained
when they were lifted above the surface. All of the
potential energy is converted into kinetic energy as it
falls, and that kinetic energy is displayed by the crater
imprint. The larger the crater diameter, the more energy
the sphere had to start off with. Use this as a guide when
you complete the analysis questions!
Quest: Understanding Gravitational Potential Energy ***
Quest: Understanding Gravitational Potential Energy ***
Quest: Understanding Gravitational Potential Energy ***
Quest: Understanding Gravitational Potential Energy ***
Quest: Understanding Gravitational Potential Energy ***
Quest: Understanding Gravitational Potential Energy ***
Quest: Understanding Gravitational Potential Energy ***
Quest: Understanding Gravitational Potential Energy ***
Quest: Understanding Gravitational Potential Energy ***
Quest: Understanding Gravitational Potential Energy ***
Quest: Understanding Gravitational Potential Energy ***
Quest: Understanding Gravitational Potential Energy ***
Quest: Understanding Gravitational Potential Energy ***
Quest: Understanding Gravitational Potential Energy ***
Quest: Understanding Gravitational Potential Energy ***
Quest: Understanding Gravitational Potential Energy ***
Quest: Understanding Gravitational Potential Energy ***
Quest: Understanding Gravitational Potential Energy ***
Quest: Understanding Gravitational Potential Energy ***
Quest: Understanding Gravitational Potential Energy ***