I need the exact value worth 20point

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

The atomic number, or number, is the described as the number of in the nucleus of an chemical element.

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?