Answer: 430 nm.
Explanation:
The relation of wavelength and frequency is:
Formula used :
where,
= frequency =
= wavelength = ?
c = speed of light = 
Now put all the given values in this formula, we get

Thus the wavelength (in nm) of the blue light emitted by a mercury lamp is 430 nm.
Answer:
3Q / 4 pi (R^3 - r^3)
Explanation:
Charge density = charge / volume
volume of a spherical shell = 
Force exerted by Justin=300 N
Here power= 600 W
distance traveled=10 m
time=5 s
power is given by P= Work done/ time
600=work/5
so work= 60x5=3000J
now work done= force* distance
3000=F *10
F= 3000/10
F=300 N
Answer:
The difference between reversible and irreversible is reversible can be changed but irreversible can not.