Universal Gravitation PhET Lab
Why everyone in this class is attracted everyone else.
Introduction:
Every object around you is attracted to you. In fact, every object in the galaxy is attracted to every other object in the galaxy. Newton postulated and Cavendish confirmed that all objects with mass are attracted to all other objects with mass by a force that is proportional to their masses and inversely proportional to the square of the distance between the objects’ centers. This relationship became Newton’s Law of Universal Gravitation. In this simulation, you will look at two massive objects and their gravitational force between them to observe G, the constant of universal gravity that Cavendish investigated.
Important Formulas:
Procedure: PhET Simulations à Play with the Sims à Physics à Gravity Force Lab
1. Take some time and familiarize yourself with the simulation. Notice how forces change as mass changes and as distance changes.
2. Fill out the chart below for various objects at various distances.
3. Solve for the universal gravitation constant, G and compare it to published values.
Remember significant digits!
Mass Object 1 Mass Object 2 Distance Force Gravitation Constant,G
56.30 kg 
52.20 kg 
3.0 m 





































Average value of G: ___________________ Units of G: ___________________
Published value of G: ___________________ Source: ___________________
How did your value of G compare to the published value you found? __________________________________
Conclusion Questions and Calculations: ½point each
1. Gravitational force is always attractive / repulsive. (circle)
2. Newton’s 3^{rd} Law tells us that if a gravitational force exists between two objects, one very massive and one less massive, then the force on the less massive object will be greater than / equal to / less than the force on the more massive object.
3. The distance between masses is measured from their edges between them / from their centers / from the edge of one to the center of the other.
4. As the distance between masses decreases, force increases / decreases.
5. Doubling the mass of both masses would result in a change of force between the masses of 8x / 6x / 4x / 2x / no change / ½x / ¼x / 1/6x / 1/8x.
6. Reducing the distance between two masses to half while doubling the mass of one of the masses would result in a change of force between the masses of 8x / 6x / 4x / 2x / no change / ½x / ¼x / 1/6x / 1/8x.
7. What is the gravitational force between two students, Dylan and Sarah, if Dylan has a mass of 75 kg, Sarah has a mass of 54 kg, and their centers are separated by a distance of .45 m? ________________ N
8. What is the gravitational force between two students, John and Mike, if John has a mass of 81 kg, Mike has a mass of 93 kg, and their centers are separated by a distance of .62 m? ________________ N
9. Imagine a 4820 kg satellite in a geosynchronous orbit. If an 85 kg piece of space junk floats by at a distance of 3.5 m, what force will the space junk feel? ________________ N
10. With what acceleration will the space junk move toward the satellite? ______________ m/s^{2}
11. With what acceleration will the satellite move (if any)? ______________ m/s^{2}
12. (harder) Using the above information and what you know about kinematics, how far will the satellite have moved when it encounters the space junk, assuming they meet, each moving with the accelerations you solved for in #10, 11? (don’t worry about them getting closer, just use #10,11) ________________ m
The moon has a mass of 7.35×10^{22} kg and is a lot farther away than is shown in textbooks. The mass of the earth is 5.97×10^{24 }kg. The moon’s mean orbit distance (centertocenter) is around the earth is 3.84×10^{8 }m. With all this information determine:
13. The gravitational force on the moon by the earth. ________________ N
14. The gravitational force on the earth by the moon. ________________ N
15. The centripetal acceleration of the moon around the earth, realizing that the gravitational force is also centripetal force. ______________ m/s^{2}
16. The speed of travel of the moon around the earth, using the formula for the speed of a moving object in a circular path. ______________ m/s
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
Assignment Help has assembled a team of highly skilled writers with diverse experience in the online writing circles. Our aim is to become a one stop shop for all your Academic/ online writing. Check out below our amazing service!
Essays
At Assignment Help, we prioritize on all aspects that creates a good grade such as impeccable grammar, proper structure, zeroplagiarism, and conformance to guidelines. The principal purpose of essay writing is to present the author's evaluation concerning a singular subject about which they have made. Since Professionalism is the mother of every success, try our team of experienced writers in helping you complete your essays and other assignments.
Admissions
Admission Papers
You have been trying to join that prestigious institution you long yearned for, but the hurdle of an admission essay has become a stumbling block. We have your back, with our proven team that has gained invaluable experience over time, your chance of joining that institution is now! Just let us work on that essay.How do you write an admission essay? How do you begin the essay? For answers, try Quality Custom Writers Now!
Editing
Editing and Proofreading
Regardless of whether you're pleased with your composing abilities, it's never an impractical notion to have a second eye go through your work. The best editing services leaves no mistake untouched. We recognize the stuff needed to polish up a writing; as a component of our editing and proofreading, we'll change and refine your write up to guarantee it's amazing, and blunder free. Our group of expert editors will examine your work, giving an impeccable touch of English while ensuring your punctuation and sentence structures are topnotch.
Coursework
Technical papers
We pride ourselves in having a team of clinical writers. The stringent and rigorous vetting process ensures that only the best persons for job. We hire qualified PhD and MA writers only. We equally offer our team of writers bonuses and incentives to motivate their working spirit in terms of delivering original, unique, and informative content. They are our resources drawn from diverse fields. Therefore your technical paper is in the right hands. Every paper is assessed and only the writers with the technical knowhow in that field get to work on it.
Coursework
College Essay Writing
If all along you have been looking for a trustworthy college essay service provider that provides superb academic papers at reasonable prices, then be glad that you search has ended with us. We are your best choice! Get highquality college essay writing from our magnificent team of knowledgeable and dedicated writers right now!
Coursework
Quality Assignment/Homework Help
We give the students premium quality assignments, without alarming them with plagiarism and referencing issues. We ensure that the assignments stick to the rules given by the tutors. We are specific about the deadlines you give us. We assure you that you will get your papers well in advance, knowing that you will review and return it if there are any changes, which should be incorporated.