Kepler’s Laws of Planetary MotionSTARTER 2

In an elliptical planetary orbit, the sun is a. at the center of the ellipse. b. on the ellipse at the intersection of the semi major axis. c. on the ellipse at the intersection of the semi minor axis. d. at the focus.

Kepler’s Laws of Planetary MotionSTARTER

A month is around thirty days because:

a. that gives a year 12 months. b. the moon orbits the Earth in about 30 days. c. the number 365 is divisible by 30. d. the lunar eclipse occurs 30 times each year.

Practice/ApplicationA. Research and write down Kepler’s Three Laws of Planetary

Motion in your science notebook. You may use the web ( hyperphysics is a good source) or any text.

B. Construct an accurate ellipse using string, cardboard, and push pens. Label the foci, the semi major axis, and the semi minor axis. Draw in the position of the Sun and an orbiting planet. Put this in your science notebook. http://www.mathsisfun.com/geometry/ellipse.html

C. Make a data table for the planets. The data should contain: 1. The mass of each planet in kg. 2. The distance in meters from the planet to the Sun. 3. The period of each planet. Put this in your science notebook.

Notebook Checklist

A.Definitions of Kepler’s 3 Laws of Planetary Motion.

B.Drawing of Ellipse Construction properly labeled.

C.Planetary Data Table with 1. The mass of each planet in kg. 2. The distance in meters from the planet to the Sun. 3. The period of each planet.

ConnectionReferring to your list of the planets and their periods, which of Kepler’s laws does this confirm?

Explain in detail.

Exit3 minute writing: Comment on why you think Kepler’s Lawsmay have guided Newton in his search for the gravitational law.