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.

The boy of mass 30 kg is at r1= 2 meters from the fulcrum. of the girl is 45 kg, at what r2 must she sit so that they are balanced ?

Scout feels ill one day before school. her mother puts a thermometer in her mouth and the temperature begins to climb to 100°f. what is happening between the cooler thermometer and scout's body? a) scout's body is applying a force to the particles in the thermometer. b) kinetic energy is being transferred from her mouth to the thermometer. c) potential energy is being lost by the thermometer and gained by scout's body. d) the potential energy stored in foods is converted to mechanical energy to raise the mercury in the thermometer.

The graph represents the distance a car travels over time while on the highway. which statement about the car's trip is accurate? a) the car does not move over time. b) the car travels at a constant velocity. c) the car's velocity increases constantly over time. d) the car's velocity decreases constantly over time.