Jackson throws a football 30 meters at a speed of 15 m/s. How long was the football in the air before Laurence caught it for touchdown

2s

Explanation:

Given parameters:

Distance  = 30m

Speed  = 15m/s

Unknown:

Time before Laurence caught it = ?

Solution:

To solve this problem;

    Speed  =  

 Time taken  =   =  = 2s

The time it takes is 2s

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.