Ascientist discovers a deep bowl-like divot under the ocean off the coast of eastern mexico that is many kilometers across. the layers of the ground all around the continent from around the time that structure formed contain large amounts of iridium and a larger number of fossils than is normally found. what most likely caused the bowl-like structure?

a meteorite impact
an asteroid impact
an iridium spike
a kuiper object impact

The density of a substance is 4.0 g/cm3. if a sample of the substance has a volume of 25 cm3 then what is the mass

Phase changes are chemical changes. true or false

Samir watches a 100-minute movie on his spaceship. maria's spaceshipe flies in the same direction as samir's spaceship but she observes his move to last 125 minutes and his spaceship to be 40 m long. how long does samir observe his own spaceship to be? according to an observer on earth, planet x is stationary. maria and samir depart earth on their spaceships at the same time, each flying at 0.5c. maria flies toward planet x and samir flies in the opposite direction. according to maria, her voyage to planet x takes 9 years. how many years does marias voyage take according to samir?