You want to create a new warming appliance that is safe. which type of electromagnetic wave would be most useful to investigate?
-x-rays
-infrared waves
-gamma rays
-ultraviolet waves

-infrared waves

Explanation:

If electromagnetic waves are arranged in order of their energy in lowest to highest order then it is as following

1) Radio waves

2) Microwaves

3) Infrared waves

4) Visible light

5) Ultraviolet waves

6) X Rays

7) Gamma Rays

So here if we wish to use to create a safe device for warming which would be of lesser and safe energy

so here correct answer would be

Infrared waves

the electric field is a “force field” around a charged object that illustrates the direction the electric force would push an imaginary 

it would be c. predictability