(a) `lambda_(e) = (6.626xx10^(-34))/(9.1xx10^(-31)xx10^(3))=727nm`
(b) `lambda_(b) = (6.626xx10^(-34))/(0.5xx10^(3))=1.33xx10^(-27)nm`
Note : `therefore (lambda_(b))/(lambda_(e))=10^(-30)`
`because` Cricket ball has much larger mass than `e^(-)` so its wavelength is very small and negligible.