Initial State: A ski jumper is at rest at the top of a ski run. Final State: A few seconds after using the poles to propel herself forward, she is
at the low point preparing to launch into her jump
Notes: The system includes the skis, the jumper, and the Earth. There is friction
acting between the ski jumper and the ski slope.
02
Directions: Tap Earrows to adjust bar heights. Tap on system to show direction of energy transfer (if
any). Tap on energy transfer arrows to adjust amount.
Tap below to ID the dir'n of
Initial State E transfer across the Final State
system boundary.
EK E, Ech
EK E, Eint
Pro
#5
System:
Skis-Jumper-Earth
Tap for
Vie
0 0 0
? E Symbols
1
0 0 0
System Arrows (?)
TO
https://prod

Chapter 23, problem 075 the figure shows a geiger counter, a device used to detect ionizing radiation (radiation that causes ionization of atoms). the counter consists of a thin, positively charged central wire surrounded by a concentric, circular, conducting cylindrical shell with an equal negative charge. thus, a strong radial electric field is set up inside the shell. the shell contains a low-pressure inert gas. a particle of radiation entering the device through the shell wall ionizes a few of the gas atoms. the resulting free electrons (e) are drawn to the positive wire. however, the electric field is so intense that, between collisions with gas atoms, the free electrons gain energy sufficient to ionize these atoms also. more free electrons are thereby created, and the process is repeated until the electrons reach the wire. the resulting "avalanche" of electrons is collected by the wire, generating a signal that is used to record the passage of the original particle of radiation. suppose the radius of the central wire is 24 âµm, the inner radius of the shell 2.3 cm, and the length of the shell 14 cm. if the electric field at the shell's inner wall is 2.8 ă— 104 n/c, what is the total positive charge on the central wire?

At very high pressures, gases become and will eventually a) more dense; become hotter b) more dense; change to a liquid or solid c) less dense; combust d) less dense; turn into a liquid

What is special about a dc circuit ?