Answer:
El valor de la fuerza que debe ejercer la persona C debe ser de -2 para que la caja esté en equilibrio físico.
Explanation:
Si la caja debe hallarse en equilibrio físico, entonces se debe satisfacer la siguiente ecuación:
(1)
Si sabemos que 
y 
, entonces el valor de la fuerza que debe ejercer la persona C debe ser:
El valor de la fuerza que debe ejercer la persona C debe ser de -2 para que la caja esté en equilibrio físico.
Answer:
39.240 W
Explanation:
Let's start by calculating the work done by the engine. We can assume that it is the same work done by the weight of the object to bring it from 40m to the surface: as much energy it takes to bring it up, the same ammount it takes to bring it down. Said work is 
At this point we can simply apply the definition of power, that is 
, to get the power of the engine is 
Velocity is distance/time
so 150/7200=.0208km/s
unless you have to convert it to miles or something else. but use the formula!
Answer:
When the Sun emits more amount of energy than normal, "Solar flares and sunspots" occur, increasing temperature of Earth. Explanation: The Earth's temperature is governed by many factors. One of these factors is 'Solar flare'.
