lecture 21 - Lecture 21 Gravity Weight Gravitational field...

Info icon This preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Lecture 21 Gravity Weight Gravitational field strength Work by gravity/gravitational potential energy Escape velocity
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
2 2 2 1 r M GM F = Gravity is the force between two masses. Gravity is a long- range or field force. No contact is needed between the bodies. The force of gravity is always attractive! r is the distance between the two masses M 1 and M 2 and G = 6.67 × 10 -11 Nm 2 /kg 2 . M 2 r M 1 F 21 F 12 . 12 21 F F - =
Image of page 2
3 Where the unit vector points from the source of the gravitational field (location of M 1 ) to the field point (location of M 2 ). r F ˆ 2 2 1 r M GM - = In vector form
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
4 Example: Three masses are arranged as shown. What is the force of mass 1 on mass 3? M 3 M 2 M 1 b a 13 ˆ r y x θ r F ˆ 2 3 1 13 r M GM - = ( 29 ( 29 y x y x r r r y x y x r ˆ cos ˆ sin ˆ ˆ ˆ ˆ ˆ ˆ ˆ 2 2 1 3 1 3 θ θ + = + + = = + = - + - = b a a b a b y y x x
Image of page 4
5 Example Continued ( 29 + + + + - = y x F ˆ ˆ 2 2 2 2 2 2 3 1 13 b a a b a b b a M GM
Image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
6 Example: Three masses are arranged as shown. What is the net force on mass 2?
Image of page 6
Image of page 7
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern