Recent content by notsam

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    Velocity of a sinussodial function

    Homework Statement A sinusoidal function of time is x = (4.7 m) cos[(0.2 rad/s)(4.5 s)] . Find the magnitude of the velocity v. Homework Equations The Attempt at a SolutionHELP! :)
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    RMS speed of Hydrogen Atoms in space

    Homework Statement In outer space the density of matter is about one atom per cm^3, mainly hydrogen atoms , and the temperature is about 2.7 K. Calculate the rms speed of these hydrogen atoms, and the pressure (in atmospheres). Homework Equations.5mv^2 = 3/2 KT The Attempt...
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    Power of Sun: Calculating Total Radiated Power

    Homework Statement [a] find the toal power radiated into space by the sun, assuming it to be a perfect emitter at T=5500 K. The Sun's radius is 7.0x10^8 m. [b] From this determine the power per unit area arriving at the earth, 1.5x10^11 m away. The Attempt at a SolutionHey guys! Sorry for...
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    What is the relationship between pressure and depth in a scuba diver's lungs?

    And I'll have to change my Volume to M^3 so that it can cancel out with the density of water. Right?
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    What is the relationship between pressure and depth in a scuba diver's lungs?

    Thanks :) Y'all are awesome.
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    Efficiency of a heat engine at high temps

    I use Kelvin correct?
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    Efficiency of a heat engine at high temps

    Ok :) At least I'm somewhat on the right track. THANKS!
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    Calculating Change in Entropy: 1100 kg Cars Colliding at 75km/hr

    Wait, how do I get Q (heat) from my mass and speed?
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    What is the relationship between pressure and depth in a scuba diver's lungs?

    Do I need to use pa or atm?
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    What is the relationship between pressure and depth in a scuba diver's lungs?

    Sorry about the power radiated by the Sun I posted this late last night. The Power radiated by the Sun went to a diffrent problem and I guess I just tagged it as this one. OK! So I think I get it So the expanded equation looks like pgh underwater*V=pgh surface* V?! YES? V at the surface is my...
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    Calculating Change in Entropy: 1100 kg Cars Colliding at 75km/hr

    Homework Statement Two 1100 kg cars are traveling 75 km/hr in opposite directions when they collide and are brought to rest. Estimate the change in entropy of the universe as a result of this collision. Assume T= 15oC Homework Equations The Attempt at a SolutionPLEASE GET ME...
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    Efficiency of a heat engine at high temps

    Homework Statement What is the maximum effciency of a heat engine whose operating tempuratures are 550oC and 365oC? Homework EquationsE=1-Thot/Tcold The Attempt at a SolutionPLEASE HELP! My thinking is that the effciency is equal two one minus the temperature in the hot resavour...
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    Rms speed of Hydrogen atoms in space

    Ok...so 1/2(mv^2)=3/2kT. But what do I use for mass?
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    Rms speed of Hydrogen atoms in space

    Homework Statement In outer space the density of matter is about one atom per cm^3, mainly hydrogen atoms , and the temperature is about 2.7 K. Calculate the rms speed of these hydrogen atoms, and the pressure (in atmospheres). Homework EquationsPV = NkT The Attempt at a...
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    What is the relationship between pressure and depth in a scuba diver's lungs?

    Homework Statement If a scuba diver fills his lungs to full capasity of 5.5 L when 8.0 m below the surface, to what volume would his lungs expand if he quickly rose to the surface? Homework EquationsP=pg(H) The Attempt at a SolutionHeyguys! :) I know that P=pgh but I have volume...