The de Broglie wavelength of a tennis ball of mass 60 g moving with a velocity of 10 metres per second is approximately

given the mass of the body=60g=60/1000 kg =.06kg
velocity of the ball =10m/s
let the de broglie wavelength be lambda
lambda=h/mv
=6.63*10^-34/(.06*10)
=11.05*10^-34 m
Thus we can see that the debroglie wvelength is very small to meausre.

When we find wavelength of tennis ballIt to too small And No instrument is available to measure this small amount of wavelength