A250 kg ball sits on a frictionless track inclined at an angle of 45 ◦ as shown in fig. 3. what is the magnitude of the force (f ) needed to keep the ball in place?

find the surface area of the sphere to the nearest square unit. use a calculator.

a. 254 in.2

b. 64 in.2

c. 127 in.2

d. 1,018 in.2

the components of a vector are the parts of the vectors that are to each other.

b perpendicular

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.