On a hot day, you are in a sealed, insulated room. the room contains a refrigerator, operated by an electric motor. the motor does work at the rate of 378 w when it is running. the refrigerator removes heat from the food storage space at a rate of 450 w when the motor is running. in an effort to cool the room, you open the refrigerator door and let the motor run continuously. at what net rate is heat added to (+) or subtracted from (−) the room and all of its contents?

Intro: a solid ball of radius rb has a uniform charge density ρ. part a: what is the magnitude of the electric field e(r) at a distance r> rb from the center of the ball? express your answer in terms of ρ, rb, r, and ϵ0. part b: what is the magnitude of the electric field e(r) at a distance r express your answer in terms of ρ, rb, r, and ϵ0. part c: let e(r) represent the electric field due to the charged ball throughout all of space. which of the following statements about the electric field are true? check all that apply. e(0) = 0 e(rb)=0 limr→∞e(r)=0 the maximum electric field occurs when r=0 the maximum electric field occurs when r=rb the maximum electric field occurs as r→∞.