Urgente por favor ayuda! Una pelota tiene un peso de 20N y empieza a recorrer el camino de A hacia B (20metros). Calcule la velocidad con la que llega al punto B si:

- La pelota fue empujada por el resorte que se encontraba con una elongación de 50cm cuando fue soltado y no hubo ningún tipo de fricción.
K= 200N/m
g= 10m/s^
Altura del punto A= 10m
Altura del punt B= 8m

Why do scientists believe that light is made of streams of particles? scientists believe that light is made of streams of particles because only the presence of photons can explain phenomena observed during experiments on the photoelectric effect. these observations include only some frequencies of light causing the ejection of electrons, no time gap existing between light striking a metal and electrons being ejected, and intensity having no effect on the kinetic energy of the ejected electrons.

Does work output exceed work input when a machine is used? a) yes, it does, as machines create energy. b) it depends on the type of machine used. c) no, it doesn’t, as machines are inefficient. d) no, it doesn’t, as machines cannot create energy.

You want to lose weight and have been trying to decide which type of fad diet is best for you. you ask your doctor, who responds that a. fad diets are a temporary fix but generally don't have any side effects b. fad diets can be used several times a year to maintain a healthy weight c. fad diets can be risky for your health and, in the long run, do not work d. fad diets should never be used one right after the other; there should be a break between them select the best answer from the choices provided. a b c d