Consider a runner in any of the lanes moving at a known, constant tangential speed. Which of the following measuring tools, if any, could be used to experimentally determine the centripetal acceleration of the runner? a. A force probe
b. A protractor protractor
c. A meterstick
d. None of these measuring tools, by themselves, can be used with the known tangential speed to determine the centripetal acceleration of the runner.

an ion is a charged atom or molecule. it is charged because the number of electrons do not equal the number of protons in the atom or molecule. an atom can acquire a positive charge or a negative charge depending on whether the number of electrons in an atom is greater or less then the number of protons in the atom.

diagram is missing, but i will try to explain your doubt.

answer:

amplitude is the maximum displacement or distance moved on a point of a vibrating body or wave measured from its equilibrium position.it is equal to half the length of vibration path.

measure their densities same density, same sub