What are super sonic speeds?

1) speeds exactly at the speed of sound

2) speeds below 343
m/s

3) speeds above 343 m/s

4) speeds at 343 m/s exactly

Which simple machine is not part of this compound machine? a. lever b. pulley c. inclined plane d. wheel and axle

Does heating a metal wire increase or decrease its electrical resistance? why?

Global climatic patterns are changing because of the melting of polar ice caps. the melting of polar ice caps is an example of the interaction between the atmosphere and cryosphere cryosphere and geosphere hydrosphere and geosphere biosphere and cryosphere