Awell-thrown ball is caught in a well-padded mitt. if the deceleration of the ball is 2.10\times 10^{4} m/s^2, and 1.85 ms \left(1\: ms=10^{-3}\: s\right) elapses from the time the ball first touches the mitt until it stops, what was the initial velocity of the ball?

38.85 m/s

Explanation:

a = Acceleration = (negative sign due to deceleration)

t = Time taken = 1.85 ms

u = Initial velocity

v = Final velocity = 0

Equation of motion

Initial velocity of the ball is 38.85 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.