What does kepler's first law of planetary motion imply? a. a planet moves at a constant speed at all points in its orbit. b. the distance that a planet is from the sun depends on the mass of the planet. c. uniform circular motion is adequate to describe the motion of all planets. d. the distance between the planet and the sun changes as the planet orbits the sun. e. planets closer to the sun than earth will show retrograde motion.

The correct answer option is D.  The distance between the planet and the Sun changes as the planet orbits the sun.

Explanation:

Kepler’s laws of planetary motion, derived by the German astronomer Johannes Kepler, are the laws of physics that describe the motions of the planets in the solar system.

According to the Kepler's first law of planetary motion: the path on which the planets orbit around the sun is elliptical in shape, with the center of the sun at one focus.

Therefore, the distance between the Sun and the planets vary as the planet orbit around the sun.

low freq = 100 mhz

low wavelength =101.7m

length = 3x10^8/freq

there are no contact forces mentioned on the list of choices that you've provided.