Learning Materials
Features
Discover
Chapter 2: Q8P (page 82)
Question:A system is acted upon by two forces,NandN. What is the net force acting on the system?
The net force acting on the system isN
Over 30 million students worldwide already upgrade their learning with 91影视!
All the tools & learning materials you need for study success - in one app.
Get started for free
Using the law of cosines, show that Eq. can be written as follows:
Whereand
are the usual spherical polar coordinates, with the z axis along the
line through. In this form, it is obvious that
on the sphere,
.
Find the induced surface charge on the sphere, as a function of. Integrate this to get the total induced charge. (What should it be?)
Calculate the energy of this configuration.
In a crash test, a truck with mass 2500kgtraveling at 24m/ssmashes head-on into a concrete wall without rebounding. The front end crumples so much that the truck is 0.72mshorter than before,
(a) What is the average speed of the truck during the collision (that is, during the interval between first contact with the wall and coming to a stop)?
(b) About how long does the collision last? (That is, how long is the interval between first contact with the wall and coming to a stop?)
(c) What is the magnitude of the average force exerted by the wall on the truck during the collision?
(d) It is interesting to compare this force to the weight of the tuck. Calculate the ratio of the force of the wall to the gravitational forceon the truck. This large ratio shows why a collision is so damaging.
(e) What approximations did you make in your analysis?
A truck driver slams on the brakes and the momentum of the truck changes from
due to a constant force of the road on the wheels of the truck. As a vector, write the net force exerted on the truck by the surroundings.
Question: The following questions refer to the circuit shown in Figure 18.114, consisting of two flashlight batteries and two Nichrome wires of different lengths and different thicknesses as shown (corresponding roughly to your own thick and thin Nichrome wires).
The thin wire is 50 cm long, and its diameter is 0.25 mm. The thick wire is 15 cm long, and its diameter is 0.35 mm. (a) The emf of each flashlight battery is 1.5 V. Determine the steady-state electric field inside each Nichrome wire. Remember that in the steady state you must satisfy both the current node rule and energy conservation. These two principles give you two equations for the two unknown fields. (b) The electron mobility
in room-temperature Nichrome is about . Show that it takes an electron 36 min to drift through the two Nichrome wires from location B to location A. (c) On the other hand, about how long did it take to establish the steady state when the circuit was first assembled? Give a very approximate numerical answer, not a precise one. (d) There are about mobile electrons per cubic meter in Nichrome. How many electrons cross the junction between the two wires every second?
What do you think about this solution?
We value your feedback to improve our textbook solutions.
Explanations 
Textbooks 
Flashcards 
91影视 AI 
Notes 
Study Plans 
Study Sets 
Find a degree 
Magazine