Se calienta una barra de hierro de 200 g y luego se coloca en 100 g de agua en un recipiente aislado. La temperatura
del agua aumenta desde los 20°C hasta los 50°C. ¿Cuál fue
la temperatura inicial en grados Celsius de la barra de
hierro? (calores específicos: hierro=450 J/Kg. K - Agua
=4186 J/Kg. K). Exprese su resultado con dos decimales.

Aplane takes off from an airport and flies to town a, located d1 = 215 km from the airport in the direction 20.0° north of east. the plane then flies to town b, located d2 = 230 km at 30.0° west of north from town a. use graphical methods to determine the distance and direction from town b to the airport. (enter the distance in km and the direction in degrees south of west.)

Aboy with a mass 25 kg climbs into a small tree. he sits on a branch that is 2.o m above to the ground. what is his gravitational potential energy above the ground?

Determine the moment of the force f about an axis extending between a and c. express the result as a cartesian vector. a is at the origin, c is at (4,3,0) and f = (4i + 12j -3k) lb coming out of b (4,3,-2).