As wavelength increase, frequency decrease
Answer:
a) 1955.6 J
b) 1955.6 J
c) 2607 N
d) 110373 J
Explanation:
a) 
b) Work done on bullet should be increase in KE = 1955.6 J
c) Work done = Force \times displacement = KE of bullet

d) Work done to stop 

Answer:
A magnet
Explanation:
is an object that can attract some metals like iron