When does heat produce a chemical change? When heat energy is transferred.
When heat changes ice into liquid water.
When heat changes the chemical composition of an object.
When heat is observed in an experiment.

2pos suppose an object in free fall is dropped from a building. its starting velocity is 0 m/s. ignoring the effects of air resistance, what is the speed (in m/s) of the object after falling 3 seconds? give your answer as a positive decimal without units. answer here