3. A spring that is originally 20 cm long is extended to a length of 25 cm when a 750g mass is hung on it.
What is the spring constant for this spring?

Most energy in an ecosystem comes originally from_

Awoman stands a distance d from a loud motor that emits sound uniformly in all directions. the sound intensity at her position is an uncomfortable 2.0×10-3 w/m2. at a distance 2.6 times as far from the motor, what are (a) the sound intensity and (b) the sound intensity level relative to the threshold of hearing?

How many hydrogen (h) atoms are in one molecule of sulfuric acid, h2so4? (1 points) 1 2 4 7