Gravitational Field Satellites Einsteins View of Gravity Physics

-Gravitational Field -Satellites -Einstein’s View of Gravity Physics Mr. Berman

Gravitational Field: Space around a mass http: //www. antonine-education. co. uk/New_items/STA/G-Field/field_2. gif

Gravitational Field Strength, g g= F m The direction of g is the same direction as F.

Problem 1: Express g in terms of F, G, m. Earth, r.

Problem 2: Find the value of the gravitational acceleration g on the surface of the earth. . The mass of the earth is 6. 0 x 1024 kg and the radius of the earth is 6. 37 x 106 m. (G=6. 67 x 10 -11 N m 2/kg 2 ).

Newton’s “Cannon” If a cannon were to be placed 150 km above sea level, and shot a cannonball with a horizontal speed of 8 km/s, the ball would fall to the earth 4. 9 m in one second. The earth’s surface curves down by the same distance, so the ball remains at the

Satellites

Satellites

Problem 3: Find the tangential velocity of a satellite, that orbits the earth at a distance r from the center of the earth. Express the answer in terms of G, me and r.

Solution:

Tangential Velocity of a Satellite at a given r do not depend on the mass of the satellite. _____ v=√(GMe/r) For a given r (distance from the earth) the speeds of the satellites are the same.

Geosynchronous Satellites: have the same period as the period of the earth. http: //www. astro. virginia. edu/class/oconnell/astr 121/guide 08 -s 04. html

Einstein’s Theory on Gravity: General Relativity http: //www. nature. com/nature/journal/v 445/n 7127/full/445468 b. html

Einstein’s Theory on Gravity: General Relativity Matter causes space to curve. Objects and light near the mass follow the curvature of space. http: //www. astro. physik. uni-goettingen. de/~hessman/Image. J/Book/Microlensing%20 -%20 Hands-On%20 General%20 Relativity/

Einstein’s View on Gravity http: //www. astronomynotes. com/relativity/s 3. htm

Black Holes Extremely massive stars with extremely high gravity.