What are some indicators that a chemical reaction is occurring? check all that apply.
a: the formation of bubbles
b: a change in size
c: a change in color
d: the formation of a liquid
e: the formation of a precipitate

Compare the horizontal displacement of the two balls as they travel to the ground. what do you observe?

Acarpenter builds an exterior house wall with a layer of wood 2.9 cm thick on the outside and a layer of styrofoam insulation 2.3 cm thick on the inside wall surface. the wood has k=0.080w/(m⋅k), and the styrofoam has k= 0.010 w/(m⋅k). the interior surface temperature is 19.0 ∘c , and the exterior surface temperature is -15.0 ∘c . a.)what is the temperature at the plane where the wood meets the styrofoam? celsius b.)what is the rate of heat flow per square meter through this wall? /m^2

Match each scenario to the form of energy it represents