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BIO Signal Propagation in Neurons. Neurons are components of the nervous system of the body that transmit signals as electric impulses travel along their length. These impulses propagate when charge suddenly rushes into and then out of a part of the neuron called an axon. Measurements have shown that, during the inflow part of this cycle, approximately 5.6 × 10 11 Na+ (sodium ions) per meter, each with charge +e, enter the axon. How many coulombs of charge enter a 1.5-cm length of the axon during this process?
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- An electroscope is a device used to measure the (relative) charge on an object (Fig. P23.20). The electroscope consists of two metal rods held in an insulated stand. The bent rod is fixed, and the straight rod is attached to the bent rod by a pivot. The straight rod is free to rotate. When a positively charged object is brought close to the electroscope, the straight movable rod rotates. Explain your answers to these questions: a. Why does the rod rotate in Figure P23.20? b. If the positively charged object is removed, what happens to the electroscope? c. If a negatively charged object replaces the positively charged object in Figure P23.20, what happens to the electroscope? d. If a charged object touches the top of the fixed conducting rod and is then removed, what happens to the electroscope?arrow_forwardAn electron with a speed of 3.00 106 m/s moves into a uniform electric field of magnitude 1.00 103 N/C. The field lines are parallel to the electrons velocity and pointing in the same direction as the velocity. How far does the electron travel before it is brought to rest? (a) 2.56 cm (b) 5.12 cm (c) 11.2 cm (d) 3.34 m (e) 4.24 marrow_forwardA sphere has a net charge of 8.05 nC, and a negatively charged rod has a charge of 6.03 nC. The sphere and rod undergo a process such that 5.00 109 electrons are transferred from the rod to the sphere. What are the charges of the sphere and the rod after this process?arrow_forward
- (a) What is the final speed of an electron accelerated from rest through a voltage of 25.0 MV by a negatively charged Van de Graff terminal? (b) What is unreasonable about this result? (c) Which assumptions are responsible?arrow_forwardA particle with charge 1.60 1019 C enters midway between two charged plates, one positive and the other negative. The initial velocity of the particle is parallel to the plates and along the midline between them (Fig. P26.48). A potential difference of 300.0 V is maintained between the two charged plates. If the lengths of the plates are 10.0 cm and they are separated by 2.00 cm, find the greatest initial velocity for which the particle will not be able to exit the region between the plates. The mass of the particle is 12.0 1024 kg. FIGURE P26.48arrow_forwardA particle of mass m and charge q moves at high speed along the x axis. It is initially near x = , and it ends up near x = +. A second charge Q is fixed at the point x = 0, y = d. As the moving charge passes the stationary charge, its x component of velocity does not change appreciably, but it acquires a small velocity in the y direction. Determine the angle through which the moving charge is deflected from the direction of its initial velocity.arrow_forward
- What is the magnitude of the strength of the electric field between two parallel conducting plates with a separation distance of 2.00 cm and having a voltage of 10 000 V? a.20 000 N/C b. 200 N/C c.20 N/C d. 2 000 N/Carrow_forwardA 2.10 10-9 C charge has coordinates x = 0, y = −2.00; a 3.06 10-9 C charge has coordinates x = 3.00, y = 0; and a -4.95 10-9 C charge has coordinates x = 3.00, y = 4.00, where all distances are in cm. Determine magnitude and direction for the electric field at the origin and the instantaneous acceleration of a proton placed at the origin. (b) Determine the magnitude and direction for the instantaneous acceleration of a proton placed at the origin (measure the angle counterclockwise from the positive x-axis). magnitude ______ Direction______arrow_forwardTwo red blood cells each have a mass of 9.05×10−14 and carry a negative charge spread uniformly over their surfaces. The repulsion arising from the excess charge prevents the cells from clumping together. One cell carries −2.70 pC and the other −2.90 pC, and each cell can be modeled as a sphere 3.75×10−6m in radius. If the red blood cells start very far apart and move directly toward each other with the same speed, what initial speed would each need so that they get close enough to just barely touch? Assume that there is no viscous drag from any of the surrounding liquid.arrow_forward
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