Which of the following statements about einstein’s explanation of the photoelectric effect is not correct? a) high-frequency photons contribute energy above the work function energy to the electron's kinetic energy. b)the energy of a photon is directly related to its frequency, thus photons below a given frequency will not have sufficient energy to cause the ejection of an electron from a metal. c) because light is packaged discretely, increasing the intensity of light will increase the number of photons hitting a metal and thus the likelihood that an electron will be ejected. d) the kinetic energy of electrons leaving the metal does not depend on the intensity of the light because intensity only affects the numbers of light packages, not their energy.

c) Because light is packaged discretely, increasing the intensity of light will increase the number of photons hitting a metal and thus the likelihood that an electron will be ejected.

Explanation:

In the photoelectric effect, light incident with a certain frequency causes the emission of photoelectrons from the surface of a metal. This effect is explained by considering light a "package" of several quanta, called photons: each photon hits only 1 electron at time, giving all its energy to the electron. If the energy given is above the work function, then the electron has enough energy to leave the metal.

The energy given off by the photon only depends on the frequency of the light, not on the intensity, according to the formula

where h is the Planck constant and f the frequency.

In this model, one photon hits only 1 electron at time: this means that the intensity of light (which is a measure of the number of photons in the light) does not affect the probability  of emitting an electron from the material, because that probability depends only on the energy of the photon, which depends only on the frequency of the light.

So, statement c) is wrong.

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards