The theory of evolution is

1. a scientific theory, meaning that it is backed by extensive evidence.
2. one of several competing scientific models that all seem equally successful in explaining the nature of life on earth.
3. essentially just a guess about how life changes through time.

An inclined plane wrapped around a metal shaft is a a. lever b. screw c. pulley d. wedge

Using a pedometer, you walk 3000 steps in 20 minutes, so your speed is 150 steps/min. each of your steps is 0.7 m long. what is your speed? 150 steps/min=/s=/h

Balloon a has charge q, and identical mass balloon b has charge 10q. you hang them from threads near each other. choose all of the statements with which you agree. check all that apply. a. a and b exert the same magnitude forces on each other. b. the force that a exerts on b is 10 times the force that b exerts on a. c. the angle between the thread supporting a and the vertical is < the angle between the thread supporting b and the vertical. d. the force that a exerts on b is 1/10 the force that b exerts on a.