Para subir una caja de 90 kg a cierta altura, un hombre utiliza como a rampa un plano inclinado de 40° con respecto a la horizontal, y ejerce una fuerza de 600N. Si el hombre desplaza la caja una distancia de 6 m en 7 segundos y el coeficiente de rozamiento entre la caja y el plano es 0,3; determinar: a. La fuerza neta que actúa sobre la caja.
b. El trabajo realizado por la fuerza neta.
c. El trabajo realizado por cada una de las fuerzas que actúan sobre el objeto.
d. El trabajo neto realizado sobre la caja.
e. La potencia del sistema debido a la fuerza neta.

Ammonia enters the expansion valve of a refrigeration system at a pressure of 10 bar and a temperature of 18oc and exits at 6.0 bar. the refrigerant undergoes a throttling process. determine the temperature, in oc, and the quality of the refrigerant at the exit of the expansion valve.

Astone is thrown into a pond. what happens to the amplitude of the resulting waves as they get farther from the point where the stone hit the water? explain.

The coulomb's law explains which of the following? select all the force between two charged objects is inversely proportional to the charge on each object. the force between two charged objects is directly proportional to the charge on each object. the force between two charged objects is directly proportional to the distance separating them. the force between two charged objects is inversely proportional to the square of the distance separat coulomb's law is similar to newton's 2nd law. if the force between two objects is f and the charge on both objects is doubled, the new force between the would now be 2f. if the force between two objects is 2f and the distance separating them is doubled, the new force between the objects would now o the be zf.