9.2  The best time to dig for clams along the seashore is when the ocean tide is at its lowest.  What phases of the Moon and what times of day would be best for clam digging?

The highest and lowest tides occur when it is either a new or a full Moon.  In both cases, low tides occur when your beach is facing maximally away from the Sun and Moon, so sunrise or sunset.

9.11  Most commercial satellites orbit Earth well inside the Roche limit.  Why are they not torn apart?