The end of which era left many plants, insects, and salamander-like animals on the Earth?

a. the Precambrian time

c. the Paleozoic era

b. the Mesozoic era

d. the Cenozoic era

Is radioactive decay used to determine absolute or relative age?

A car travel 30km south, 15km west and 10km north what is the average of the car

Which is an indication that a chemical change to a substance has occurred? A. It changes shape. B. New substances are formed. C. Energy is used or given off. D. both B and C

What causes the cycle of seasons on Earth?

What data are needed to calculate the actual mechanical advantage of a machine

A roller coaster is entering a vertical loop which has a radius of 25.0 m. If the coaster is traveling at 45.0 m/s as it enters the loop, how much is the centripetal force that you experience? (Assume your mass to be 75.

Which best describes tropical continental climate during the summer? A. clear, dry weather, B. cloudy, wet weather, C. cold, dry weather, D. hot, dry weather

At the beach, describe where or when you would see wave fronts. How are wave fronts useful to surfers?

How would the moon appear from earth if the moon did not rotate?

Block B has mass 4.00 kg and sits at rest on a horizontal, frictionless surface. Block A has mass 2.00 kg and sits at rest on top of block B. The coefficient of static friction between the two blocks is 0.400.