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A proton’s speed as it passes point A is 50,000 m/s. It follows the trajectory shown in FIGURE P25.43. What is the proton’s speed at point B?
Living cells “pump” singly ionized sodium ions, Na+, from the inside of the cell to the outside to maintain a membrane potential
a. How much work must be done to move one sodium ion from the inside of the cell to the outside?
b. At rest, the human body uses energy at the rate of approximately 100 W to maintain basic
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Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (Chs 1-42) Plus Mastering Physics with Pearson eText -- Access Card Package (4th Edition)
- A charged particle is moved in a uniform electric field between two points, A and B, as depicted in Figure P26.65. Does the change in the electric potential or the change in the electric potential energy of the particle depend on the sign of the charged particle? Consider the movement of the particle from A to B, and vice versa, and determine the signs of the electric potential and the electric potential energy in each possible scenario.arrow_forwardTwo point charges, q1 = 2.0 C and q2 = 2.0 C, are placed on the x axis at x = 1.0 m and x = 1.0 m, respectively (Fig. P26.24). a. What are the electric potentials at the points P (0, 1.0 m) and R (2.0 m, 0)? b. Find the work done in moving a 1.0-C charge from P to R along a straight line joining the two points. c. Is there any path along which the work done in moving the charge from P to R is less than the value from part (b)? Explain.arrow_forwardA Consider a thin rod of total charge Q and length L (Fig. P26.43). Show that the electric potential at point P, a distance x from the end of the rod, is given by V(x)=kQLln(x+Lx) FIGURE P26.43 Problems 43 and 54.arrow_forward
- A source consists of three charged particles located at the vertices of a square (Fig. P26.32), where the square has sides of length 0.243 m. The charges are q1 = 35.0 nC, q2 = 65.0 nC, and q3 = 56.5 nC. Find the electric potential at point A located at the fourth vertex. FIGURE P26.32 Problems 32 and 33.arrow_forwardRank the potential energies of the four systems of particles shown in Figure OQ20.6 from largest to smallest. Include equalities if appropriate. Figure OQ20.6arrow_forwardThree particles with equal positive charges q are at the corners of an equilateral triangle of side a as shown in Figure P20.10. (a) At what point, if any, in the plane of the particles is the electric potential zero? (b) What is the electric potential at the position of one of the particles due to the other two particles in the triangle? Figure P20.10arrow_forward
- An infinite number of charges with |q| =2.0 C are placed along the x axis at x = 1.0 m, x = 2.0 m, x = 4.0 m, x = 8.0 m, and so on, as shown in Figure R26.79. What will be the electric potential at x = 0 if the consecutive charges have alternating signs as shown in Figure P26.79? Hint: Use the mathematical formula for a geometric series, 1+r+r2+r3+r4+=11r FIGURE P26.79arrow_forwardFigure P26.71 shows three charged particles arranged at the vertices of an isosceles triangle with base b = 1.00 m. What is the electric potential due to the particles at point P, which is at the midpoint of the base? FIGURE P26.71arrow_forwardTwo 5.00-nC charged particles are in a uniform electric field with a magnitude of 625 N/C. Each of the particles is moved from point A to point B along two different paths, labeled in Figure P26.65. a. Given the dimensions in the figure, what is the change in the electric potential experienced by the particle that is moved along path 1 (black)? b. What is the change in the electric potential experienced by the particle that is moved along path 2 (red)? c. Is there a path between the points A and B for which the change in the electric potential is different from your answers to parts (a) and (b)? Explain. FIGURE P26.65 Problems 65, 66, and 67.arrow_forward
- A filament running along the x axis from the origin to x = 80.0 cm carries electric charge with uniform density. At the point P with coordinates (x = 80.0 cm, y = 80.0 cm), this filament creates electric potential 100 V. Now we add another filament along the y axis, running from the origin to y = 80.0 cm, carrying the same amount of charge with the same uniform density. At the same point P, is the electric potential created by the pair of filaments (a) greater than 200 V, (b) 200 V, (c) 100 V, (d) between 0 and 200 V, or (e) 0?arrow_forwardAn infinite number of charges with q = 2.0 C are placed along the x axis at x = 1.0 m, x = 2.0 m, x = 4.0 m, x = 8.0 m, and so on, as shown in Figure P26.78. Determine the electric potential at the point x = 0 due to this set of charges. Hint: Use the mathematical formula for a geometric series, 1+r+r2+r3+r4+=11r FIGURE P26.78arrow_forward(a) Find the potential difference VB required to stop an electron (called a slopping potential) moving with an initial speed of 2.85 107 m/s. (b) Would a proton traveling at the same speed require a greater or lesser magnitude potential difference? Explain. (c) Find a symbolic expression for the ratio of the proton stopping potential and the electron stopping potential, Vp/Ve. The answer should be in terms of the proton mass mp and electron mass me.arrow_forward
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