Question

Find the wavelength of radiation emitted when an electron from infinity falls
to stationary state (n=1) in a hydrogen atom. (RH = 1.09 x 107 m-1
)

Answer 1

Total height =100m=S1+S2

Using equation of motion,

For first ball

S1=ut+21gt2

where,

S= Distance

u= Initial velocity

g= acceleration due to gravity

t= time

S1=0−21gt2

For second ball

S2=40t+21gt2

S2=40t−S1 ..(i)

Putting the value of S1 in equation (i)

S2+S1=40t

100=40t

t=2.5sec

Hence, two balls will meet after 2.5sec