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A sample of material is found to be 26,700 years old using carbon dating. What fraction of the original 14/6C remains

N/Nsubscript0=?

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Stuck on a problem in this physics assignment. Unsure whether or not I should use the ?t' = t / sqrt (1- v^2/c^2).

Problem~

An elementary particle called a pi meson (or pion for short) has an average lifetime of 2.6 10-8 s when at rest. Suppose that a pion moves with a speed of 0.9c relative to Earth.

(a) Find the average lifetime of the pion as measured by an observer on Earth.

s

(b) Find the average distance traveled by the pion as measured by the same observer.
m

(c) How far would the pion have traveled relative to Earth if relativistic time dilation did not occur?
m

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In Fig. 12-45, a nonuniform bar is suspended at rest in a horizontal position by two massless cords as shown in the figure here. One cord makes the angle ? = 24.1° with the vertical; the other makes the angle f = 65.9° with the vertical. If the length L of the bar is 4.4 m, compute the distance x from the left end of the bar to its center of mass.

this is the link of the figure:
http://edugen.wiley.com/edugen/courses/crs4957/art/qb/qu/c12/qu12_c.jpg

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Figure 12-52a shows a horizontal uniform beam of mass m_b and length L that is supported on the left by a hinge attached to a wall and on the right by a cable at angle ? with the horizontal. A package of mass m_p is positioned on the beam at a distance x from the left end. The total mass is m_b + m_p = 60.2 kg. Figure 12-52b gives the tension T in the cable as a function of the package's position given as a fraction x/L of the beam length. The scale of the T axis is set by Ta 500 N and Tb 700 N. Evaluate (a) angle ?, (b) mass m_b, and (c) mass m_p.

this is the link of the figure:
http://edugen.wiley.com/edugen/courses/crs4957/art/qb/qu/c12/fig12_53.gif

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1. A steel cable on a bridge has a length of 40 m on a cool night when the temperature is 5° C but in the heat of the day when it is 40° C it expands, what is the change in length of the cable?
(Linear expansion of steel is a = 12 x 10-6 /C°)

2. A pan full of water has a volume of 3.8 liters at 2 °C is heated to 98 °C without boiling, what is the change in volume of the water? (Volume expansion of water is ß = 207 x 10-6 /C°)

3. A square hole is cut out of a sheet of aluminum, the hole has a length and width of 10.000 cm (A = 100.000 cm2) when it is starts out, the sheet is cooled down to room temperature (20 °C) and the new area is 97.8044 cm2) , what was the original temperature of the aluminum sheet? (aAl = 23 x 10-6/°C)

thank you in advance

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Home >All Categories > Science & Mathematics >Physics >Open Question Jessica Walsh Member since:September 27, 2010Total points:269 (Level 2)a) How relative velocity is related to the direction in which rockets are launched or send into space ( provide 4 examples)
part b) the benefits to society and the environment of using specific direction for launching rockets? (provide 4 examples)Answer Question

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1. A steel beam 2 cm x 2cm and 1.5 m long fits tightly between two pieces of concrete at 15 °C, what force is generated by the beam when it heats up to 35 °C in the hot sun? (Ysteel = 2.0 x 1011 N/m2, asteel = 12 x 10-6/°C)
(assume concrete does not expand)

2. If 25,000 J of heat energy is added to 0.5 kg of water at 10 °C what is the new temperature of the water?
(cwater = 4,186 J/kg°C)

thank you!!

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I don't understand it at all. I'm in regular High school physics, so If you can explain it that'd be great.

A scuba diver uses a waterproof flashlight to shine a ray of light so it strikes the surface of the water at an angle of incidence. Use Snell's law to fin the angle of incidence that would give and angle of refraction for the refracted ray to be directed right along the surface, and show that the angle of incidence is the same as the critical angle for total internal reflection.

No numbers, so, no clue... lol

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Home >All Categories > Science & Mathematics >Physics >Open QuestionHow can you calculate the specific heat capacity of an unknown metal? In my question the metal with a mass of 50g and a temperature of 200 degrees celsius was placed in 125 g of water with an initial temperature of 20 degrees celsius. After the simulation and the metal was placed in the water, the temperature of the water rose from 20 to 28.35. How can I find the specific heat capacity of the unknown metal? I don't need a full solution, just a formula or guideline on how to go about solving this. Thank you.Answer Question

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I had to make a comic strip to demonstrate momentum/energy, but my scanner is too small for my comic strip. I'll describe it, though. But I have a hard time understanding physics myself so it may no be accurate, and it's kind of unrealistic and corny. Please tell me what I can do to improve it. Thanks!

It centers around two sports commentators at a baseball game.

Bob: Helloooo, baseball fans! Today the Blue Jays are hosting the New York Yankees! Man, I am pumped for this game. You know, Bill, I happened to read online last night the physics behind baseball, and ---

Bill: . . . . Bob, you said you wouldn't---

Bob: Did you see that pitch?! Beautiful! The batter has a chance to knock the ball from the park --- oh! So close!

Bill: *murmur* Tell me about it. I thought you were going to get into one of your physics moods---

Bob: *interrupts* Well, the batter can only apply so much force, but it's possible to magnify the impulse greatly by increasing the amount of time of which the force is delivered.

Bill: . . . .

Bob: That --- I mean impulse --- is th change in momentum, Bill. The batter must cause a significant amount of impulse.

Bill: *sigh* Why, Bob? Give us baseball fans a physics lesson.

Bob: Why? Well, the greater the impulse, the greater chance the batter has at getting a home run.

Bill: . . . Really. . . .? *thinks:* He's going to jinx the game. . . . We'll be lucky if we get one run in now.

Bob: And would you look at that! A home run!!! Way to go, Bautista!

Bill: Haha! Yes!! So, the increase in the time interval resulted in a more powerful impact!

Bob: That's the spirit! Plus, the baseball and bat are colliding head-on in a relatively elastic situation!

Bill: . . . . Okay, that's enough physics. Let's just watch the game!

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Home >All Categories > Science & Mathematics >Physics >Open Question notmy realname Member since:November 14, 2010Total points:368 (Level 2)Would a shift of weight from one planet to another nearby planet( E.g. from Mars to Earth) cause a change in the orbit of either planet? My question pertains to the idea of scavenging other planets for resources and bring them to this planet on a large scale. Would the shift of weight of such a great magnitude change the orbit of either planet or their rotations?Answer Question

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Hey,
I recentely posted a question on yahoo answers regarding phase shift from two microphones.

Steve answered my question through email but unfortunatly I cannot reply! Therefore, if you're reading this, thank you very much! :)

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Inches? Pounds? I pity you and your compatriots.

/useless answer

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Home >All Categories > Science & Mathematics >Physics >Open Question Britney Member since:August 12, 2009Total points:846 (Level 2)I'm a freshmen in high school and i am taking physics. Physics is very diffcult but i still want to take the regents because i heard it looks good on your transcript. But if i fail the regents what would happen? Would i be able to take it again? And would it be on my transcript if i failed it?Answer Question

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Home >All Categories > Science & Mathematics >Physics >Open Question grizzle Member since:February 03, 2011Total points:94 (Level 1)Find the minimum diameter of an l = 16.2 m long brass wire that will stretch no more than 8.89 mm when a mass of 376 kg is hung on the lower end. (Hint: The Young's modulus of brass is 91.0 GPa.)
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