Un calefactor eléctrico de 1kW tiene resistencias calefactoras que están "al rojo" a 900°C. Suponiendo que el 100% de la potencia útil se deba a la radiación y que las resistencias actúen como cuerpos negros. Hallar el área efectiva de la superficie radiante. Considerar que la temperatura ambiente es de 20°C.

Phase changes are chemical changes. true or false

During spring semester at mit, residents of the parallel buildings of the east campus dorms battle one another with large catapults that are made with surgical hose mounted on a window frame. a balloon filled with dyed water is placed in a pouch attached to the hose, which is then stretched through the width of the room. assume that the stretching of the hose obeys hooke's law with a spring constant of 89.0 n/m. if the hose is stretched by 5.80 m and then released, how much work does the force from the hose do on the balloon in the pouch by the time the hose reaches its relaxed length? unitst 3 number-1497 the tolerance is +/-5% open show work click if you would like to show work for this question:

Eddy whose mass is 55kg climbs up the 1.50 meter high stairs in 2s. calculate eddy’s power rating