Answer:
B. use light of a shorter wavelength.
Explanation:
We know that

h= plank's constant
c= speed of light
λ= wavelength of the incident light
so, in order to have sufficient energy for for the emission of electron, the incident's radiation must have λ small enough.
B. use light of a shorter wavelength.
Answer:
According to the data given in the question, experiment on table two pulling and falling masses are arranged in the fig. 250 g is pulling right side and 100 g pulling down. The gravitational force is common to both the masses, so we cannot say that the block moves towards heavier mass, also the block does not move towards the lighter mass.
Obviously, the effect of heavier mass of 250 g is more on the block, so the block moves towards right bottom corner. i.e., diagonally between two masses
please find the attachment.
in china, there is a family limit for only having 1 child
at 10 billion people on earth, we will most likely run out of food supply
This shifts the star’s spectral lines toward the blue end of the spectrum. If the star is moving away from us, it’s waves are effectively stretched out when they reach earth, increasing their wavelength. This shifts the star’s spectral lines toward the red end of the spectrum.
The light coming out of a concave lens will never meet.
So, the answer is A. will never meet.
Happy Studying! ^^