Answer
while the earth's orbit is almost circular and little seasonal change arises here from our changing distance from the sun, which of these planets would find its northern hemisphere summer solstice much colder than its southern hemisphere one, due to larger changes in perihelion and aphelion?

a) venus (eccentricity = .007)
b) mars (eccentricity = .093)
c) jupiter (eccentricity = .048)
d) neptune (eccentricity = .010)

Describe the path of a ray that approaches a mirror parallel to the principal axis.

Acave rescue team lifts an injured spelunker directly upward and out of a sinkhole by means of a motor-driven cable. the lift is performed in three stages, each requiring a vertical distance of 10.0 m: (a) the initially stationary spelunker is accelerated to a speed of 4.90 m/s; (b) he is then lifted at the constant speed of 4.90 m/s; (c) finally he is decelerated to zero speed. how much work is done on the 68.0 kg rescue by the force lifting him during each stage?

Which accurately compares concave and convex lenses?