Answer Happy

And One short-answer problem are from past the material of Chapters 20-23, the material of Exam 12. Shock To The System Finley is standing, barefoot, on wet ground, when lightning strikes nearby. A large charge is deposited in a small area in the ground. This creates a large electric field in the surrounding earth. Multiple-Choice Question The diagram shows equipotential lines from the charge deposited in the ground. On the diagram, there are 4 possible placements of Finley's bare feet. Which of these placements would give the smallest current through Finley's body? f Short-Answer Problem If the potential on the ground at the position of Finley's left foot is 800 V and the potential at their right foot is 600 V, what will be the current through, and the potential difference across their torso? Assume a skin resistance of 1000 12. a Send Me A Signal For this problem, we'll use the following data: The distance between nodes on a myelinated axon is 1.0 mm. The axon is a tube of radius 5.0 um filled with fluid of resistivity 2.0 A-m. The myelin sheath surrounding the axon has a thickness of 3.0 um. Let's consider a segment of axon between two nodes. When the left node experiences an action potential, the potential inside the axon rises to +40 mV; at the right node, the potential is -70 mV. This difference in potential drives a current along the interior of the axon. +40 mV 70 mV Multiple-Choice Question The current is due to the motion of positive ions, which move at a constant speed. What energy transformation does this imply? A. Potential energy to kinetic energy B. Kinetic energy to potential energy C. Potential energy to thermal energy D. Thermal energy to potential energy Short-Answer Problem At the instant shown in the diagram, what is the magnitude of the current inside the axon?
Un Up And Away Certain spiders deploy long strands of silk to catch a breeze and travel through the air, this is called ballooning. Certain spiders preferentially deploy silk to balloon when the electric field near the earth is high. This field can provide an upward force on the silk, which acquires a charge when it emerges from the spider's spinneret. If the field is large enough, the spider will experience a not upward force. Let's look at some typical numbers: A 20-cm-long strand of silk that a 0.20 mg spider has deployed has a total charge of +1.0 nC, and the field near the surface of the earth is 6,000 N/C, directed upward. Multiple-Choice Question If we say that the potential at the ground is zero, the potential 10 m above the ground will be A Greater than zero. B. Equal to zero. C. Less than zero. Short-Answer Problem For the numbers given, how does the magnitude of the weight force compare to the magnitude of the electric force? What is the direction of the net force? A-7 10 ko VE? I Saw The Light In lab, you saw a circuit that used a photoresistor; the figure from the lab showing this circuit is reproduced here. There is a battery providing current to the circuit, a 10 k2 resistor, a photoresistor (with the arrows pointing toward it), and meters to measure current (A-2) and voltage (V=?). Assume that the battery in the circuit provides 3.0 V. When light shines on the photoresistor, the resistance decreases. Let's assume the following values: When the room lights are off, the resistance is 30 kg; in normal room light, the resistance drops to 5.0 k 2. Multiple-Choice Question If the brightness of the light in the room increases, how do the meter readings change? A. Measured current increases, measured voltage increases. B. Measured current increases, measured voltage decreases. C. Measured current decreases, measured voltage increases. D. Measured current decreases, measured voltage decreases. Short-Answer Problem What is the voltage measured by the voltmeter for each of the following conditions: Room lights off Normal room light . .