Download presentation

Published byColin Casey Modified over 4 years ago

2
Sample Determine the net gravitational force acting on the Earth during a total lunar eclipse. msun = 1.99 x1030 kg mmoon = 7.36 x 1022 kg rsun = 1.5 x 108 km rmoon = km

3
Kepler ( ) Used Tycho Brahe's precise data on apparent planet motions and relative distances. Deduced three laws of planetary motion. Took him the last 30 years of his life.

4
Kepler’s First Law The orbits of the planets are elliptical (not circular) with the Sun at one focus of the ellipse. 'a' = semi-major axis: Avg. distance between sun and planet

5
**Kepler’s First Law Perihelion – close to sun (perigee)**

Aphelion – furthest from sun (apogee) Eccentricity – how not a circle are you? circle e = 0 parabola e = 1

6
**Kepler’s First Law Examples: Earth: e = 0.0167 Mercury: e = 0.2056**

Venus: e =

7
Kepler’s First Law a = semi-major axis

8
**Translation: planets move faster when closer to the Sun.**

Kepler's Second Law A line connecting the Sun and a planet sweeps out equal areas in equal times. slower faster Translation: planets move faster when closer to the Sun.

9
Kepler's Second Law A line connecting the Sun and a planet sweeps out equal areas in equal times. The speed of the planet in orbit is dependent on its distance from the sun voro = vf rf slower faster

10
Sample If the Earth has an orbital speed of 29.5 km/sec at apogee, determine the orbital speed at apogee. ra = 1.52 x 108 km rp = 1.47 x 108 km

11
Kepler’s Second Law voro = vf rf Note where the highest speeds of tornados and hurricanes are.

12
Kepler’s Third Law The square of a planet’s orbital period is proportional to the cube of its semi-major axis . Translation: the further the planet is from the sun, the longer it will take to go around

13
Why Does it Work? Newton discovers that ellipses are pretty close to circular, just with the sun offset Fc = Fg

14
Sample How fast must a satellite move to maintain an orbit of 500 km over the Earth’s surface? What is the period of rotation?

15
Kepler’s Third Law Newton took the idea of centripetal force and applied it to the Kepler problem Fc = Fg

16
**Solution . Where M is the mass being orbited (as opposed to orbiting)**

T is the period of the orbit r is the radius of the orbit

Similar presentations

OK

Acceleration - rate of change of velocity (speed or direction), occurs any time an unbalanced force is applied.

Acceleration - rate of change of velocity (speed or direction), occurs any time an unbalanced force is applied.

© 2018 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on external gear pump Ppt on programmable logic device Ppt on mauryan architecture Ppt on obesity prevention programs Ppt on content development definition Ppt on obesity prevention cdc Ppt on interesting facts of india Ppt on causes of 1857 revolt ppt Download ppt on equations of motion Ppt on k-map simplification