If a ball with an original velocity of zero is dropped from a tall structure and takes 7 seconds to hit the ground, what velocity does the ball have when it reaches the ground? a. 156.8 m/s b. 68.6 m/s c. 34.3 m/s d. 240.1 m/s

What is the scientific definition of energy that relates to work

Identify the theory that can be used to explain each phenomenon. answers diffraction: wave theory interference: wave theory reflection: both particle and wave theories refraction: both particle and wave theories

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.