(a) calculate the number of photoelectrons per second ejected from a 1.00-mm 2 area of sodium metal by 500-nm em radiation having an intensity of 1.30 kw/m2 (the intensity of sunlight above the earth’s atmosphere).
(b) given that the binding energy is 2.28 ev, what power is carried away by the electrons?
(c) the electrons carry away less power than brought in by the photons. where does the other power go? how can it be recovered?

answer: at 24 february, 2014 the population gets twice of its initial population.

explanation:

since we have given that

the population for alpha city, t years after january 1, 2004 is given as

first we find out the initial population, i.e. t=0,

so, our quadratic equation becomes,

according to question, we have said that if the population has twice its initial population, then it becomes

so, time taken to reach this above mentioned population is given by

now, we know that time can't be negative so, we take t=9.149 years.

hence, at 24 february, 2014 the population gets twice of its initial population.

see earlier answer

false br

the answer is the first electromagnet (a). this is because it has more coils around the ferromagnetic material. increasing the number of coils increases the surface area in which the metal interacts with the current in the coil. this enables more atoms in the metal to become aligned hence becoming more magnetized.