4. the box is pushed 20.0 m up a 30.0° ramp (same surface as o
0 20.0 m up a 30.0° ramp (same surface as before) at a constant speed of 4.00 m/s. the applied force
is parallel to the surface of the ramp.
a. how much net force is exerted on the box?

b. how much force is applied to the box to keep it moving?

real, smaller and upside-down.   so the answer should be b.

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.