15. If the frequency of a sound wave in air at STP remains constant, the wave's energy can be
varied by changing its
(1) amplitude
(3) wavelength
(2) speed
(4) period

This is for my 8th grade science class, i really don’t understand. can someone me? , lol.

Assume that two of the electrons at the negative terminal have attached themselves to a nearby neutral atom. there is now a negative ion with a charge -2e at this terminal. what are the electric potential and electric potential energy of the negative ion relative to the electron? the electric potential and the electric potential energy are both twice as much. the electric potential is twice as much and the electric potential energy is the same. the electric potential is the same and the electric potential energy is twice as much. the electric potential and the electric potential energy are both the same. the electric potential is the same and the electric potential energy is increased by the mass ratio of the oxygen ion to the electron. the electric potential is twice as much and the electric potential energy is increased by the mass ratio of the oxygen ion to the electron.

Hat is the most commonly cited cause of occupational injuries in the healthcare sector? a. repositioning of patients b. manual pipetting c. slips and trips d. workplace violence