Answer:
(a) 5.04 eV (B) 248.14 nm (c) 
Explanation:
We have given Wavelength of the light \lambda = 240 nm
According to plank's rule ,energy of light


Maximum KE of emitted electron i= 0.17 eV
Part( A) Using Einstien's equation
, here
is work function.
= 5.21 eV-0.17 eV = 5.04 eV
Part( B) We have to find cutoff wavelength



Part (C) In this part we have to find the cutoff frequency

Time = (distance) / (speed)
= (30 km) / (30 m/s)
= (30,000 m) / (30 m/s)
= (30,000 / 30) sec
= 1,000 seconds
= 16 minutes 40 seconds
Answer:
change in mass = 2.41*10^{8}kg
Explanation:
The change in the mass can be computed by using the relation
(1)
That is, the energy liberated comes from the mass of the nuclear fuel. The energy generated in one year is

Hence, by replacing in the equation (1) you have (c=3*10^{8}m/s)

HOPE THIS HELPS!!