What do the EM results indicate about what might is causing this disease?

In the event of a disease caused by an unknown pathogen, it is hard to know which reagent to pick. ... EM, though it may not be able to identify a virus beyond the family level, at least ... Negative staining of stool specimens from these cattle demonstrated a ... This results in a fuzzy halo around the particles in negative stains.Explanation:

frequency = 0.5 /s

speed = 2m/s

Explanation:

frequency = 1/period = 1/2 = 0.5 /s

speed = frequency × wavelength

= 0.5 × 4 = 2m/s