Solution
In general d sin ? = m? and y = D tan?
since ? <ə, ym ~ D ?m ~ m ? D/d
for ?1=480 nm, D=1.0m, d=5.0 mm y3 = 3(480x 10-9)(1.0)/5.0 x 10-3)= 2.88 x 10-4 m
for ?2=600 nm, D=1.0m, d=5.0 mm y3 = 3(600x 10-9)(1.0)/5.0 x 10-3)= 3.60 x 10-4 m
hence difference is .072 mm