A 4.0 kg mass is released from rest at the top of a frictionless ramp 2.0 m above ground. It slides down the ramp to a level, horizontal portion of frictionless track and then collides with a stationary 8.0 kg mass. Immediately after the collision, the larger mass has a velocity v_l = +3.5 m/s (i. e., heading to the right).
The velocity v_s of the smaller mass just after the collision:

A) -0.74 m/s B) +0.74 m/s C) -2.6 m/s D) +2.6 m/s E) 0 m/s

(A)−0.74m/s

Explanation:

We are given that

Mass ,=4 kg

Distance, d=2 m

We have to find the velocity of smaller mass just after the collision.

Initial velocity of smaller mass,u=0

Velocity of smaller mass at the bottom

According to law of conservation of momentum

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.