What organisms disappeared duing Precambrian

What is the difference between a flat line in a distance/time graph, and a speed/time graph?

A car traveling at 7.3 m/s accelerates at the rate of 0.82 m/s2 for an interval of 7.4 s. Find vf.

A spaceship takes off vertically from rest with an acceleration of 30.0 m/s 2. What magnitude of force F is exerted on a 53.0 kg astronaut during takeoff?

A 1.20 g sample of an unknown has a volume of 1.73 cm what is the density of the unknown

Forgetting takes place only in short-term memory.

How many earth years does it take mars to orbit the sun

Which represents a system that is almost completely closed?

If many household substances classify as acids or bases what is the ph scale

A protostar forms once the nebular cloud condenses and the core begins

How do whales bats and dolphins use echolocation? A To scare away predators B To attract mates C To orient them selves and find food D To tell animals of there species where they are