Name: ______________________________________ Date: ________________________
Student Exploration: Gravitational Force
Vocabulary: force, gravity, vector
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
On the night of a Full Moon, Mary decides to do an experiment with gravity. At midnight, she climbs into her backyard tree house, leans out the window, and holds an acorn as high as she can. She lets go and is disappointed to see the acorn plummet back down to Earth.
1. Why did the acorn fall to Earth instead of rising up to the Moon? ______________________
_________________________________________________________________________
2. Give two reasons why we feel Earth’s gravity more strongly than the Moon’s gravity.
_________________________________________________________________________
_________________________________________________________________________
Gizmo Warmup
From acorns to apples, gravity causes nearly any object to fall to Earth’s surface. Gravity also causes the Moon to orbit Earth and Earth and the other planets to orbit the Sun. The Gravitational Force Gizmo™ allows you to explore the factors that influence the strength of gravitational force.
To begin, turn on the Show force vector checkboxes for objects A and B. The arrows coming from each object are vectors that represent gravitational force. The length of each vector is proportional to the force on each object.
1. Move object A around. As object A is moved, what do you notice about the direction of the two force vectors? __________________________________________________________
2. How do the lengths of the two vectors compare? __________________________________
3. Drag object A closer to object B. How does this change the gravitational force between the two objects? ______________________________________________________________
Activity A:
Gravity and mass 
Get the Gizmo ready: · Turn on Show vector notation for each object. · Check that each object’s mass (m_{A} and m_{B}) is set to 10.0 × 10^{5} kg. 

Question: How does mass affect the strength of gravitational force?
1. Form hypothesis: How do you think the masses of objects A and B will affect the strength of the gravitational force between them? __________________________________________
_________________________________________________________________________
2. Predict: How do you think the gravitational force between two objects will change if the mass of each object is doubled? ____________________________________________________
3. Measure: Turn on Show grid. Place object A on the x axis at 20 and object B on the x axis at 20. The force on object A is now 0.0417i + 0j N. That means that the force is 0.0417 newtons in the x direction (east) and 0.0 newtons in the y direction (north).
A. What is the magnitude of the force on object A? F_{A} = _______________________
B. What is the magnitude of the force on object B? F_{B} = _______________________
4. Gather data: You can change the mass of each object by clicking in the text boxes. For each mass combination listed in the table below, write magnitude of the force on object A. Leave the last two columns of the table blank for now.
m_{A} (kg) 
m_{B} (kg) 
F_{A} (N) 
Force factor 
m_{A}× m_{B} (kg^{2}) 
10.0 × 10^{5} kg 
10.0 × 10^{5} kg 



10.0 × 10^{5} kg 
20.0 × 10^{5} kg 



20.0 × 10^{5} kg 
20.0 × 10^{5} kg 



20.0 × 10^{5} kg 
30.0 × 10^{5} kg 



5. Calculate: To determine how much the force is multiplied, divide each force by the first value, 0.0417 N. Round each value the nearest whole number and record in the “Force factor” column.
Next, calculate the product of each pair of masses. Fill in these values in the last column. Compare these numbers to the “Force factor” numbers.
(Activity A continued on next page)
Activity A (continued from previous page)
6. Analyze: How much does the force increase if each mass is doubled? _________________
_________________________________________________________________________
7. Analyze: How do the force factors compare to the products of the masses? _____________
_________________________________________________________________________
_________________________________________________________________________
8. Apply: What would you expect the force to be if the mass of object A was 50.0 × 10^{5} kg and the mass of object B was 40.0 × 10^{5} kg? ________________________________________
Check your answer with the Gizmo.
9. Draw conclusions: How do the masses of objects affect the strength of gravitational force?
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
10. Summarize: Fill in the blank: The gravitational force between two objects is proportional to the _________________________ of the masses of the objects.
11. Apply: Suppose an elephant has a mass of 1,800 kg and a person has a mass of 75 kg. If the strength of gravitational force on the person was 735 N, what would be the gravitational force on the elephant? (Assume both the person and elephant are on Earth’s surface.)
_________________________________________________________________________
Show your work:
Activity B:
Gravity and distance 
Get the Gizmo ready: · Turn on Show distance. · Set m_{A} and m_{B} to 10.0 × 10^{5} kg. 

Question: How does distance affect the strength of gravitational force?
1. Form hypothesis: How do you think the distance between objects A and B will affect the strength of the gravitational force between them? __________________________________
_________________________________________________________________________
2. Predict: How do you think the gravitational force between two objects will change if the distance between the objects is doubled? ________________________________________
3. Measure: Place object A on the x axis at 5 and object B on the x axis at 5.
A. What is the distance between the two objects? ________________________
B. What is the magnitude of the force on object A? F_{A} = ________________________
4. Gather data: For each set of locations listed below, record the distance and the force on object A. Leave the last two columns blank for now.
Object A 
Object B 
Distance (m) 
F_{A} (N) 
Force factor 
1 Distance^{2} 
(5, 0) 
(5, 0) 




(10, 0) 
(10, 0) 




(15, 0) 
(15, 0) 




(20, 0) 
(20, 0) 




5. Interpret: How does increasing the distance affect the force? _________________________
_________________________________________________________________________
6. Calculate: To calculate the force factor, divide each force by the original force (0.667 N). Write each force factor with three significant digits. Next, calculate the reciprocal of the square of each distance and fill in the last column of the table. Write each of these values with three significant digits as well. (The unit of 1/distance ^{2} is square meters, or m^{2}.)
(Activity B continued on next page)
Activity B (continued from previous page)
7. Analyze: Compare the force factors to the 1/distance^{2} values in your table. What is the relationship between these values?
_________________________________________________________________________
_________________________________________________________________________
8. Apply: What would you expect the force to be if the distance was 50 meters? ____________
Use the Gizmo to check your answer.
9. Make a rule: Based on the measured force between objects that are 10 meters apart, how can you find the force between objects that are any distance apart?
_________________________________________________________________________
_________________________________________________________________________
10. Summarize: Fill in the blanks: The gravitational force between two objects is proportional to the ____________________ of the distance ____________________
11. Challenge: In activity A, you found that the gravitational force between two objects is proportional to the product of their masses. Combine that with what you have learned in this activity to complete the universal formula for the force of gravity below. (Hint: In the equation, G is a constant.) Check your answer with your teacher.
F_{Gravity} = G ×
12. On your own: Use the Gizmo to find the value of G in the formula above. List the value and describe how you found it below. The units of G are newton · meter^{2} ÷ kilograms^{2}, or N·m^{2}/kg^{2}. Check your answer with your teacher.
G = _____________________
Show your work:
Why Work with Us
Top Quality and WellResearched Papers
We always make sure that writers follow all your instructions precisely. You can choose your academic level: high school, college/university or professional, and we will assign a writer who has a respective degree.
Professional and Experienced Academic Writers
We have a team of professional writers with experience in academic and business writing. Many are native speakers and able to perform any task for which you need help.
Free Unlimited Revisions
If you think we missed something, send your order for a free revision. You have 10 days to submit the order for review after you have received the final document. You can do this yourself after logging into your personal account or by contacting our support.
Prompt Delivery and 100% MoneyBackGuarantee
All papers are always delivered on time. In case we need more time to master your paper, we may contact you regarding the deadline extension. In case you cannot provide us with more time, a 100% refund is guaranteed.
Original & Confidential
We use several writing tools checks to ensure that all documents you receive are free from plagiarism. Our editors carefully review all quotations in the text. We also promise maximum confidentiality in all of our services.
24/7 Customer Support
Our support agents are available 24 hours a day 7 days a week and committed to providing you with the best customer experience. Get in touch whenever you need any assistance.
Try it now!
How it works?
Follow these simple steps to get your paper done
Place your order
Fill in the order form and provide all details of your assignment.
Proceed with the payment
Choose the payment system that suits you most.
Receive the final file
Once your paper is ready, we will email it to you.
Our Services
No need to work on your paper at night. Sleep tight, we will cover your back. We offer all kinds of writing services.
Essays
No matter what kind of academic paper you need and how urgent you need it, you are welcome to choose your academic level and the type of your paper at an affordable price. We take care of all your paper needs and give a 24/7 customer care support system.
Admissions
Admission Essays & Business Writing Help
An admission essay is an essay or other written statement by a candidate, often a potential student enrolling in a college, university, or graduate school. You can be rest assurred that through our service we will write the best admission essay for you.
Reviews
Editing Support
Our academic writers and editors make the necessary changes to your paper so that it is polished. We also format your document by correctly quoting the sources and creating reference lists in the formats APA, Harvard, MLA, Chicago / Turabian.
Reviews
Revision Support
If you think your paper could be improved, you can request a review. In this case, your paper will be checked by the writer or assigned to an editor. You can use this option as many times as you see fit. This is free because we want you to be completely satisfied with the service offered.