Need !
: science
you can tell if an object is in motion if

a. it appears to move backward when another object moves forward
b. its reference point is in motion
c. its reference point is stationary
d. its position changes relative to a reference point

D

Explanation:

An object can be seen as in motion when compared to a reference point. For example, you can tell the car you are sitting in is in motion by watching as the road seems to be moving under you.

coil wire, increase current, put iron inside the coil

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