Answer:
For Total energy and momentum to be conserved, the minimum energy of the photons released is equal to twice the rest mass energy of an electron that is 
The annihilation of electron -positron cannot produce a single photon. It is prohibited by the law of conservation of energy and momentum.
All wavelengths and frequencies of electromagnetic radiation ...
including visible light ... are features of the electromagnetic spectrum.
Sound waves have nothing to do with the electromagnetic spectrum.
Answer:
b. negative
Explanation:
neutrons have a negative charge and protons have a proton has a positive charge
Answer:
Explanation:
We are not told where A and B are, but I'll assume that they are two points on the orbit of earth about the sun.
As that orbit is an ellipse, the two points likely do not have the same distance between the earth and sun.
As gravity varies with the inverse of the square of the distance (F = GMm/d²), the force at the closer distance will be greater than the force at the longer distance.
Weight and mass are used synonymously on earth because the value of g is constant on the earth because the weight of a body is the amount of force exerted by the Earths gravity on an object of finite mass. And, the mass of an object gives the amount of matter in the body and is measured in kilograms.
