Question

From a cliff that is 10.0m above a lake, a boy (mass 40 kg) jumps from rest, straight down into the water. At the instant, he strikes the water, what is his de-Broglie wavelength? `(g=10ms^(-2)) h=6.62xx10^(-34)Js`

Answer 1

Correct Answer - `1.17xx10^(-36) m`
Here, `y=10.0m , m=40g`
velocity of boy before entering the water is
`v=sqrt(2gy)=sqrt(2xx10xx10)=10sqrt(2)m//s`
De-broglie wavelength, `lambda=h/(mv)`
`:. lambda=(6.6xx10^(-34))/(40+10sqrt(2))=1.167xx10^(-36)m`