A 4.6-mm-diameter proton beam carries a total current of 1.8 mA . The current density in the proton beam, which increases with distance from the center, is given by J=Jedge(r/R) , where R is the radius of the beam and Jedge is the current density at the edge. Part A How many protons per second are delivered by this proton beam? Express your answer using two significant figures.

Which is not one of the major climate zones? question 3 options: rain forest polar tropical temperate

How does the kinetic energy of a charge change as the charge moves under the effect of an electric field from higher potential to lower potential? a. the kinetic energy increases. b.the kinetic energy decreases. c.the kinetic energy remains the same. d.the kinetic energy is always zero.

Which best describes the first law of thermodynamics as compared to the second law of thermodynamics? a. the first law describes how thermal energy is conserved but not the direction it moves. b. the first law describes the direction thermal energy moves but not how it is conserved. c. the first law describes how thermal energy can be created but not how it can be destroyed. d. the first law describes how thermal energy can be destroyed but not how it can be created.