A lab technician needs to clean medical instruments that have been exposed to bacteria. Which electromagnetic wave
would be most useful for this task?

Ultraviolet wave

Explanation:

Ultraviolet waves would be best used to sterilize a surface expose to bacteria because it will completely destroy them.

Most medical equipment are usually sanitized by using this rays because the DNA of most bacteria can be innervated upon exposure to these ray.

Ultraviolet rays are energetic and more powerful than the normal visible light and subsequent long wavelength radiations.

Generally, ultraviolet rays is a very harmful electromagnetic radiation.  

the total distance traveled by the car is

30km + 49km = 79 km .

r = ρ x length / area  

ρ = r x area / length  

ρ is in ohm-meters  

in basic units, it is m³kg/s³a²  

i think this is it.