Under certain circumstances, potassium ions (K+) in a cell will move across the cell membrane from the inside to the outside. The potential inside the cell is − 65.5 mV and the potential outside the cell is zero.

a. What is the change in the electrical potential energy of a single potassium ion as it moves across the membrane?
b. Does the potential energy of the potassium ions increase, decrease, or remain the same as the ions move from the inside to the outside?

Three different objects, all with different masses, are initially at rest at the bottom of a set of steps. each step is of uniform height . the mass of each object is a multiple of the base mass : object 1 has mass 4..00m , object 2 has mass 1..96m , and object 3 has mass . when the objects are at the bottom of the steps, define the total gravitational potential energy of the three-object system to be zero. if the objects are then relocated as shown, what is the new total potential energy of the system? each answer requires the numerical coefficient to an algebraic expression. each algebraic expression is given using some combination of the variables , , and , where is the acceleration due to gravity. enter only the numerical coefficient. (example: if the answer is 1..23mgd , just enter 1.23)

Asolid round steel rod 6.25 mm in diameter and 375 mm long is rigidly bonded to the end of solid square brass rod 25 mm on a side and 300 mm long. the geometric axes of the bare are along the same line. an axial tensile force of 5.4 kn is applied at the extreme ends of the assembly. for steel e = 200 gpa and for brass e = 90 gpa. determine the total elongation for the assembly.

The voltage applied across a given parallel-plate capacitor is doubled. how is the energy stored in the capacitor affected?