Question

2. How fast would a 0.25 kg football have to be traveling to have the same momentum as a 0.05 kg bullet travelling 500 m/s?

Answer 1

Their momentum would be equal. so, 
m1v1 = m2v2
0.25 * v1 = 0.05 * 500
v1 = 25 / 0.25
v1 = 100 m/s

In short, Your Answer would be 100 m/s

Hope this helps!