Weighing a Bacterium Scientists are using tiny, nanoscale cantilevers 4 micrometers long and 500 nanometers wide-essentially miniature diving boards-as a sensitive way to measure mass. The cantilevers oscillate up and down with a frequency that depends on the mass placed near the tip, and a laser beam is used to measure the frequency. A single E. coli bacterium was measured to have a mass of 710 femtograms = 7.10×10−16 kg with this device, as the cantilever oscillated with a frequency of 17.1 MHz .
Treating the cantilever as an ideal, massless spring, find its effective force constant.