Which of the following is x rays not useful for
a inspecting packages
b detecting pipeline cracks
c producing vitamin d
d diagnosing bone fractures

X-rays are not used for producing Vitamin D. (C)

prolly a beacuse the momentuem the car has increases while going down hill

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.