si un barco crucero de turismo se encuentra a 30 km de la costa cuando suena su sirena ¿cuánto demora el sonido en llegar a la costa?

Hellosubatomic particles  are  particles  that are smaller than the atom. protons, neutrons, and electrons are the three mainsubatomic particles  found in an atom. protons have a positive (+)  charge. an easy way to remember this is to remember that both neutron and no  electrical charge  start with the letter "n."have a nice day

Can you give more detail  

Idon't know the answer google it

D) the event horizon, a large planet and the chute located between the two.