Sound travels 2146 m through a material in 1.4 seconds. what is the material?

In a system, when potential energy decreases, then entropy also decreases. true false

Avolcano erupts next to a grassland area in a valley. a. describe three ways in which material released by the volcano could impact the grassland area. b. describe three ways in which the grassland ecosystem could recover after a volcanic eruption.

What is the force that opposes motion and works against the downward pull? a) friction b) gravity c) weight d) acceleration