Question

1. which season is it in the southern hemisphere when the suns rays strike most directly?

a. spring
b. summer
c. autumn
d. winter

1. scientists have discovered a new planet. the amount of time in one day on this planet would be determined by

a. its radius
b. the tilt of its axis
c. its period of rotation
d. its period of revolution

Explanation:

For question 18: When the sun's rays strike most directly (solar declination is highest for a hemisphere), in the Southern Hemisphere, it is summer. In the Northern Hemisphere, when the sun's rays strike most directly, it is summer there, but seasons are opposite in the Southern Hemisphere.
For question 19: The length of a day on a planet is determined by its period of rotation. The period of rotation is the time it takes for a planet to complete one full spin around its axis. The radius affects the size - related properties like surface area and volume but not the day - length. The tilt of the axis affects seasons, and the period of revolution (time to orbit the sun) affects the length of a year.

Answer:

1. b. summer
2. c. Its period of rotation