How does the strong nuclear force hold the nucleus of an atom together?

a. it overcomes the electrical force of repulsion between protons in the nucleus.
b. it overcomes the electrical force of attraction between protons in the nucleus.
c. it overcomes the electrical force of repulsion between electrons in the nucleus.

What is the energy of a photon of ultraviolet radiation with a frequency of 4.4 × 1015 hz? planck’s constant is 6.63 × 10–34

How do the kidneys affect homeostasis

Asolid cylinder and a cylindrical shell have the same mass, same radius, and turn on frictionless, horizontal axles. the cylindrical shell has light-weight spokes connecting the shell to the axle. a rope is wrapped around each cylinder and tied to blocks of equal masses that are held the same height above the ground. both blocks are released simultaneously. the ropes do not slip. which block hits the ground first? or is it a tie?