why do signs at petrol stations warn people not to use cell phones while filling the petrol in their cars?

Astudent is given an assignment to demonstrate diffraction. he takes a photograph of a straw in a glass of water. the straw appears bent at the water level. which best describes this example? a) this is a good example of diffraction. b) this is an example of dispersion and not diffraction. c) this is an example of refraction and not diffraction. d) this is an example of reflection and not diffraction.

** urgent** the voltage across the primary winding is 350,000 v, and the voltage across the secondary winding is 17,500 v. if the secondary winding has 600 coils, how many coils are in the primary winding? a- 30 coilsb- 583 coilsc- 12,000 coilsd- 332,500 coils

Argon, neon, and xenon are examples of