A 2.0 kg yo-yo swings in a vertical circle on the end of a 1.0 m string. At the bottom of its swing the yo-yo has a speed of 4.0 m/s. What is the force of tension in the string at this point?

the chart show the masses and velocities of two colliding objects that stick together after a collision.

according to the law of conservation of momentum, the momentum of the object after the collision is  

answer

1,500

kg • m/s.

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.