Which object represents a heterogeneous mixture? A. Metal rings

B. Brass key

C. Steel wood

D. Aluminum pans

If the speed of a particle triples ,by what factor does its kinetic energy increase?

Aheavy boy and a lightweight girl are balanced on a massless seesaw. the boy moves backward, increasing his distance from the pivot point. what happens to the seesaw? it is impossible to predict without knowing additional information. the side the boy is sitting on will tilt downward. the side the girl is sitting on will tilt downward. nothing; the seesaw will remain balanced.

What is the answer to these problems 30 pt