The driver of a car traveling at 30.5 m/s slams on the brakes so that the car undergoes a constant acceleration, skidding to a complete stop in 4.5 s.
What is his average acceleration?

i believe the answer is electric potential.

explanation:

pythagoras' theorem

square root (-5^2+9^2)

square root (25+81)

square root (106)

angle is tan^-1(9/5)

neg x, pos y

the answer is the first electromagnet (a). this is because it has more coils around the ferromagnetic material. increasing the number of coils increases the surface area in which the metal interacts with the current in the coil. this enables more atoms in the metal to become aligned hence becoming more magnetized.