Aproton is released from rest inside a region of constant, uniform electric field e 1 pointing due north. 27.3 s after it is released, the electric field instantaneously changes to a constant, uniform electric field e 2 pointing due south. 3.03 s after the field changes, the proton has returned to its starting point. what is the ratio of the magnitude of e 2 to the magnitude of e 1 ? you may neglect the effects of gravity on the proton.

Under conditions for which the same room temperature is maintained by a heating or cooling system, it is not uncommon for a person to feel chilled in the winter but comfortable in the summer. provide a plausible explanation for this situation (with supporting calculations) by considering a room whose air temperature is maintained at 20â°c throughout the year, while the walls of the room are nominally at 27â°c and 14â°c in the summer and winter, respectively. the exposed surface of a person in the room may be assumed to be at a temperature of 32â°c throughout the year and to have an emissivity of 0.90. the coefficient associated with heat transfer by natural convection between the person and the room air is approximately 2 w/m2 â‹…â‹… k. what is the ratio of the thermal resistance due to convection to the thermal resistance due to radiation in the summer? what is the ratio of thermal resistances in the winter

5g of ammonium nitrate was dissolved in 60g of water in an insulated container. the temperature at the start of the reaction was 23.0°c and at the end it was 19.0°c. calculate the energy absorbed by the reaction.

True or false graphs must include scales that increase by the same amount