Can someone out? will give brainliest

Always use significant figure rules. remember that these rules apply to all numbers that are measurements. if a vector that is 3 cm long represents 30 km/h, what velocity does a 5 cm long vector which is drawn using the same scale represent? a.100 km/h b.60km/h c.50km/h

What did hunter gathers do to alter the environment?

Up until 1938, paleontologists accepted the idea that coelacanths (an ancient fish) went extinct at the time that they last appear in the fossil record, about 80 million years ago. but in 1938, a live coelacanth was discovered off the coast of south africa that was compared to the fossil record and found to be the same species what goal of science does this discovery represent