Tuesday, March 16, 2010

Physics Gravity Assignment

REMINDER: Both classes had to finish the problems that we did not go over from the Gravity packet. I will be checking them on Friday.

After we go over the Universal Gravitation homework, each class will be working on the computers.

Multimedia Science School
Physics
Fields
Gravitational Fields
Lesson
Gravitation

Each group must submit a summary of what they learned, including comments about something completely new or surprising that they found out. The summary must include each student's name and then submit via comments to this posting. Submit as "anonymous".

If you finish that assignment before time runs out, go to the website below for a great review of the material.

Lesson 3 – Universal Gravitation
Lesson 4 – Planetary and Satellite Motion

YOU WILL HAVE A QUIZ ON GRAVITY AND CIRCULAR MOTION ON TUESDAY, MARCH 23rd!

(Review packets #6 and #7. Go here to review also -
Lesson 1 and 2 are Circular Motion. (Lesson 3 and 4 for Gravity are listed above.)

1. Talisha Peeler & Sara Atehortua
In this lesson we learned that the gravitational field is an area around an object where another mass will experience gravitational force. We also now know that the closer together the fields are the stronger the forces are too. No matter what, magnitude and direction in the field always stay the same. And lastly, the direction of the field is vertically downward at any point on the surface.

2. Bryan DeVissiere
Hernan Gandarilla
Alex Soares
Sindy Trujillo
Period 1

During this lesson, we learned about the gravitational field and its components. The gravitation field is the area around an object where another mass will experience a gravitational force. The field is represented by field lines which show the direction of the force on a mass in the field. And thus, simply stated, the closer together the field lines, the stronger the force on the mass. The field strength is the gravitational force per unit (1 kg) mass. This can be written as g = F/m. This field strength at any point is proportional to the mass m1 of the object causing the field, and inversely proportional to the square of the distance r to the point from the centre of the object. This can be written as g = Gm1/r2. The force on a mass m2 in the field is given by F = gm2, which gives F = Gm1m2/r2. Now, the gravitational potential at any point in the field is given by V = –Gm1/r. Throughout this summary we’ve been using the variable G and not know exactly what it means. G is the gravitational constant and its value is 6.67 × 10–11 N m2 kg–2. In relation to little g, the gravitational field strength close to the center of the earth is, in magnitude, g = 9.81 N kg–1. Because the variation in the gravitational field strength is going to be in the negative phase, the potential energy gained by an object moving in the gravitational field can be taken to be directly proportional to the increase in height: (delta)Ep = mg(delta)h. If an object of mass m2 is travelling with speed v in a circular orbit of radius r around a planet of mass m1, then the centripetal force F = m2v2/r is equal to the gravitational force on the object F = Gm1m2/r2.

3. Marissa Martinez
Naelia Barragan
Nefertiti Ferguson-Goforth
Lizzette Martinez

Newton's universal law of gravitation can be summarized with the equation F = Gm1m2/r2, where F is the force between the two objects, m1 and m2 are their masses and r is the distance between them. This was in fact one or Newton’s many great achievements his formulation of this gravitational law. When investigating the gravitational field around a planet change the further an object is from a planet the smaller the force. Therefore the total force surrounding the planet is greater. Field strength is defined as force per unit (1 kg) mass or g = F/m. Size has no effect on the gravitational field and the force exerted on an object because the amount of force stays the same whether the planet is big or small. The field strength is inversely proportional to the square of the distance from the center of the planet. The value of G will always stay constant at 6.67 × 10–11 N m2 kg–2. Each point in a gravitational field has gravitational potential which means that it is work done in bringing unit mass (1 kg) from infinity to that point. Gravitational potential (V) is calculated from the equation V = –Gm1/r, where G is the gravitational constant, m1 is the mass of the planet and r is the distance from the center of the planet. The potential energy of a mass m2 at any point is given by Ep = m2V. Gravitational potential energy increases steadily with height and is directly proportional to height. Increases in gravitational potential energy are directly proportional to the increase in height and mass. The surface of the Earth the gravitational field strength is nearly constant in magnitude, g = 9.81 N kg–1.

4. Sherwin Yu, Emmanuel Torres
We found out that the gravitational field is the area between a object and another mass that expirences a gravitational force.Gravitational field strength at any point is proportional to the mass m1of the object causing the field. If a rocket goes too fast it will fly out of earth's orbit and if it's too slow it will go crashing back down to Earth.

5. Alyssa Zargos, Kevin Andrade, Mohammed Hamid

One of Isaac Newton's great achievements was his formula for the universal law of gravitation. Newton's universal law of gravitation can be explained with the equation F = Gm1m2/r2, where F is the force between the two objects, m1 and m2 are their masses and r is the distance between them. The gravitational field is the area around an object where another mass will experience a gravitational force. There is a force exerting on a mass in the field which is represented by field lines. The closer together the field lines, the stronger the force on a mass. The gravitational force per unit mass is the gravitational field strength. If you get really far away from the Earth the force of gravity on you gets to be nothing and you would no longer be pulled towards the Earth, so you no longer have energy that can be changed back to another form. Gravitational potential V is calculated from the equation V = –Gm1/r, where G is the gravitational constant, m1 is the mass of the planet and r is the distance from the centre of the planet. The potential energy of a mass m2 at any point is given by Ep = m2V.

The field close to the surface of the Earth, is the gravitational field strength that is almost constant in magnitude, g = 9.81 Nkg-1. The gravitational field strength and the acceleration due to gravity always have the same value. The field strength varies, and as it decreases as the height increases. Potential energy gained depend on the mass of the object is proportional to the mass. The increase in gravitational potential energy is directly proportional to the increase in height and mass. This can be written ΔEp = kmΔh, where k is a constant of proportionality, m is the mass and Δh is the increase in height.

Centripetal force is F = m2v2/r and the force of gravity F = Gm1m2/r2. Those two equations are equal to each other if an object of mass m2 is travelling with speed v in a circular orbit of radius r around a planet of mass m1. In the multimedia picture, the spacecraft orbited around the earth. As the speed increases, the rocket goes into an elliptical orbit which takes it further from the Earth. The speed needed to keep the spacecraft orbiting around earth is 3073 m s–1. For all circular orbits round a particular planet of mass m1, there is only one orbit with any specific value of speed, radius or period. Law of gravitation, gravitational field strength, gravitational potential energy, and centripetal force is very important when dealing with the force of objects and more specifically objects in space.

6. Elizabeth Trejo
Phyllisse Lewis
Roneisha Handy
Precious Humphrey

We learned that the gravitational field is the area around an object where another mass would experience a gravitational force. The closer field lines are to each other, the stronger the force on the mass. The formula for gravitational field strength is g= F/m. F stands for the gravitational force and m stands for the mass. The gravitational field strength at any point on the field is equal to the mass of the object causing the field, which can be written as g= Gm/r2. The universal constant of gravitation, G, is 6.67 x 10-11 N m2 kg-2 . Close to the earth’s surface, the gravitational field strength is approximately equal to 9.8 N kg-1. When an object travels in a circular orbit around a planet of mass, the gravitational force on the object can be figured out by using the equation: F= Gm1m2/r2.

7. Margarita Rodriguez
Victoria Taiwo
Kevin D.
Aldrin M.

The gravitational field is the round area of an object where another mass will experience a gravitational force. Field lines show the direction of the forceon a mass on the field represents the field. Then when the force on the mass becomes stronger and this is because the field lines are closer together. Gravitational force can be found g=F/m. Where F is force and m is mass. The gravitational constant can be written as G and the constant is 6.67*10^-11 N m ^2 kg^-2. Acceleration due to gravity is always the same to magnitude and direction. The direction of the field is vertically downwards at any point on the surface. The centripetal force is can be written in the as F=m2v^2/r. Where F is force, m is mass,v is the velocity, and r is the radius. The grvitational force can be written as F=Gm1m2/r^2. Where G is the gravitational constant, m1 is the first mass, m2 is the second mass, r is the radius.

~It is surpring that the centripetal force is equal to the gravitational force.-Margarita

~I found it surprising that for all circular orbits round a particular planet mass m1, there is only one orbit with any specific value of speed, radius or period.-Kevin

~I think it is interesting that the feild is represtented by feild lines which shows the direction of the force on a mass in the feild!-Victoria

~I found it surprising how a geostationary satellite remains above a fixed point on the Earth's equator with an orbital period of 24 hours- Aldrin

8. Boronny Touch
Sergio Munoz
Allen Ngu

In this lesson, we learned that gravitational force is directed towards the center of the planet. The closer the field lines are to each other, the stronger the gravitational force. The field is the same at the same distance from the center of the planet whether the body is extended or compressed. We have potential energy because we do work against gravity to get to a certain point. An object field strength always decreases as the height increase, since the field lines of the Earth’s surface it always directed downwards and it never varies with the height. There is a very small percentage of the field strength in addition we also learned that the field strength is measure in force per unit mass. The gravitational field strength and the acceleration of gravity is the same all the time. The gravitational potential energy gains energy as the height of the field lines are increasing. An object that travels in circular orbit has a centripetal force (F= m2v2) that is equal to the gravitational force (F=Gm1m2/r2) on the objects. All objects in circular orbit around a certain planet of mass, only has any specific value of speed, radius or period. The geostationary satellite remains a certain point above the earth’s equator with a 24 hour period of orbit. In conclusion we learned a series of formulas. For example, delta Ep=mg delta h, which shows the correlation between the potential energy, mass, acceleration due to gravity, and the change in height. We also learned that G is the gravitational constant is equal to 6.67 × 10–11 N m2 kg–2.

9. Eunice Polanco, Cynthia Garcia, Courtney Manns, Dondre Edwards, Angelo Faiella

The area around an object where another mass will experience gravitational force is known as a gravitational field.

When field lines are close together, the force is greater on the mass.

G is the gravitational constant. Its value is 6.67 x 10 ^ -11 Nm squared kg to the negative 2.

Magnitude and direction of the field strength, along with the acceleration due to gravity are always equal, or the same.

At any point on the surface, the direction of the field is always vertically down.

The gravitational field strength is nearly constant in magnitude when closer to the surface of the Earth which is g=9.81 N kg^-1.

If an object of mass m2 is traveling with speed v in a circular orbit of radius r around a planet of mass m1 then the centripetal force F=m2v2 /r is equal to the gravitational force on the object F=Gm1m2/r2

For all circular orbits round a particular planet of mass m1, there is only one orbit with any specific valve of speed, radius or period.

A geostationary satellite remains above a fixed point on the Earth’s equator with an orbital period of 24hrs.

The gravitational field is the area round an object where another mass will experience a gravitational force.

The field is represented by field lines which show the direction of the force on a mass in the field.

The closer together is the field lines, the stronger the force on the mass.

Gravitational field strength at any point is proportional to the mass (m1) of the object causing the field, and inversely proportional to the square of the distance r to the point from the centre of the object. This can be written as g = Gm1/r2

The force on the mass (m2) in the field is given by F = gm2, which gives F = Gm1m2/r2

The gravitational potential at any point in the field is given by V = -Gm1/r

G is the gravitational constant and its value is 6.67 x 10-11 N m2 kg-2
Close to the surface of the Earth the gravitational field strength is nearly constant in magnitude, g = 9.81 N kg-1

The magnitude and direction of the field strength, and the acceleration due to gravity is always the same.

The direction of the field is vertically downwards at any point on the surface.

Because the variation in the gravitational field strength is negligible, the potential energy gained by an object moving in the gravitational field can be taken to be directly proportional to the increase in height.

ΔEp = mgΔh

If an object of mass m2 is traveling with speed v in a circular orbit of radius r around a planet of mass m1, then the centripetal force F = m2v2/r is equal to the gravitational force on the object F = Gm1m2/r2

For all circular orbits round a particular plant of mass m1, there is only one orbit with any specific value of speed, radius or period

A geostationary satellite remains above a fixed pint on the Earth’s equator with an orbital period of 24 hours.