How long ago did homo sapiens first appeared in the fossil record? identify the era in which this occurred.

Acommercial passenger jet can travel up to 970 km/hr at an altitude of 30,000 feet. at this speed, how long will it take the jet to travel 1,865 kilometers? a. 2.3 hrs b. 1.9 hrs c. 1.7 hrs d. 1.5 hrs

Using the free-body diagram, calculate the net force acting on the sled. is the sled in a state of dynamic equilibrium?

How do you count the total number of atoms present on one side of a chemical equation?