An object moving at 30 m/s takes 5s to come to a stop. what is the object's acceleration?
a. 30 m/s ^2
b. -30 m/s ^2
c. -6 m/s ^2
d. 6 m/s ^2

adding a(n) to an electric circuit would increase the magnetic field around a wire;

b. solenoid

a solenoid is a type of electromagnet whose purpose is to generate a controlled magnetic field.

if the purpose of the solenoid is instead to impede changes in the electric current, a solenoid can be more specifically classified as an inductor rather than an electromagnet.