Recent content by Wobble

  1. W

    Thermodynamics: Adiabatic Compression

    It's supposed to be in Kelvin? I feel dumb now. I got them both. Thank you for your help.
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    Thermodynamics: Adiabatic Compression

    Homework Statement The engine of a Ferrari F355 F1 sports car takes in air at 20.0 *C and 1.00 atm and compresses it adiabatically to 0.0900 times the original volume. The air may be treated as an ideal gas with \gamma = 1.40. Find Final Temp and Final Pressure Homework Equations...
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    Torque/Intertia: Balancing a Tire

    Looking a wikipedia 1. (2piR)/V=T 2. (2piV)/a=T 3. a=(v^2)/R and for it in radians per second 4. omega=2pi/T So do I just want equation 3, substitute it into F=ma, and get (M+m)(v^2/R)=answer for C? It says "frequency of the vibration" though, which doesn't sound like a force answer...
  4. W

    Torque/Intertia: Balancing a Tire

    Torque= R cross F= I times alpha Alpha is then a/R. But I need a velocity in there somehow to solve part C. 50mph isn't an angular velocity, nor does a/R contain velocity in it. How do I account for the change in the center of mass? Its going to involve my answer to A somehow, which I got to...
  5. W

    Torque/Intertia: Balancing a Tire

    Well, I could say that the perfect tire's R for the center of mass equation is 0, and that would just give me 0 as the center of mass. Then the center of mass for the two objects would be: (M*0+m*R)/(M+m) and that would give me my new center of mass, which would be the distance between the...
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    Torque/Intertia: Balancing a Tire

    Well for the center of mass of the tire, I don't really have a radius for it? The mass m is 1 ft away from the center of the tire, but how far away is mass M from the center of the tire? Do I use 1 ft for it a well? But then I would get (M+m)/(M+m) which is just 1... (\Sigmamr)/(\Sigmam) is...
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    Torque/Intertia: Balancing a Tire

    Homework Statement Homework Equations \Sigma\tau= r x F = I*\alpha Angular Momentum L= r x p = r x mv = r x mr\omega = mr2 * \omega2 editediteditediteditediteditediteditediteditediteditediteditedit This formatting looks weird. It should be r^2 *(omega)^2 and I*(alpha for the next part)...
  8. W

    Nudging an Asteroid. Conservation of Momentum

    Ok cool. I said something different earlier, but you went with the correct numbers.
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    Nudging an Asteroid. Conservation of Momentum

    I found an error. The mass of the asteroid times rocket velocity is 5*10^13, NOT 5*10^7 5*10^7 is the mass of the rocket times the rocket velocity.And why would I divide 5*10^13 by 2*10^10, when 2*10^10 is what I multiplied the velocity by in the first place? Or is the rocket mass times...
  10. W

    Nudging an Asteroid. Conservation of Momentum

    Or it just means we don't have the technology yet to alter the course of something so massive.
  11. W

    Nudging an Asteroid. Conservation of Momentum

    So a.) is 5*10^7, b.) is 2.5*10^-3 and c.) is the amount of time to get 10,000 km well if the velocity is 2.5*10^-3 10,000 km = 10,000,000 m 10 million divided by the velocity is the amount of time to move that far. So 10million/2.5*10^-3= 4*10^9 seconds. Am I correct with which answers go...
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    Nudging an Asteroid. Conservation of Momentum

    In my notes for this class, the only related thing I have is a rocket burning fuel. m(dV/dt)= -vex(dm/dt) where vex is the exhaust velocity. The problem i have with this though, is that the mass does change (rocket burning fuel), but you said that was negligible. Then after that step...
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    Nudging an Asteroid. Conservation of Momentum

    Wait, so is 50million the answer to question A? I feel like I'm so close to understanding, but I have no idea how to get the change in velocity in terms of the mass.
  14. W

    Nudging an Asteroid. Conservation of Momentum

    So... multiplying the burn speed by the mass of Apophis results in 5*107 What good is this number? edit: Do I set the initial side equal to this value to find the initial velocity of the asteroid?
  15. W

    Nudging an Asteroid. Conservation of Momentum

    Those are the two different mass values. What do you mean by "< <"
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