Recent content by Dotty21690

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    Simple harmonic motion and amplitude

    thanks! but then how would I find part b? would I find the kinetic energy of the bullet and the mechanical energy of the system(in which I would plug back in my value for the amplitude?)
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    Simple harmonic motion and amplitude

    Homework Statement A 2.10-kg block is suspended from a spring with a spring constant of 280.0 N/m. A 0.070-kg bullet is fired into the block from directly below with a speed of 220.0 m/s and is embedded in the block. Find the amplitude of the subsequent motion. -What fraction of the...
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    Calculating Net Gravitational Force on a Sphere from Multiple Particles

    I know I'm doing something wrong...but I don't know what it is.
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    Calculating Net Gravitational Force on a Sphere from Multiple Particles

    for the 20 kg to the 71 kg: F = (6.67E-11Nm^2/kg^2*20kg*71kg)/(.5m^2)=.000000379 (and this should be negative since its in the negative y direction and there is no x force) for the 20kg to the 432 kg: F =(6.67E-11Nm^2/kg^2*20kg*432kg)/(sqrt(2)m^2)=.000000288 (negative because below x-axis)...
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    Calculating Net Gravitational Force on a Sphere from Multiple Particles

    Homework Statement The masses and coordinates of three particles are as follows: 20.0 kg, (0.50, 1.00) m; 432.0 kg, (-1.00, -1.00) m; 71.0 kg, (0.00, -0.50) m. What is the gravitational force on a 20.0 kg sphere located at the origin due to the other spheres, magnitude and direction? Give...
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    Rotation of a planet, kinetic energy

    turns out I did divide the wrong way! but I wonder why I was told the answer was wrong when I did put in 2.140*10-6, hmm. But thanks guys!
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    Rotation of a planet, kinetic energy

    turns out the answer was 2.140*10-6, which I had got at one time, but it said it was wrong :( but I don't know how to get that answer again. so can someone help me with this one?
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    Rotation of a planet, kinetic energy

    well I showed the work earlier to get the answers for the KErot and KE, then I divided. I'll post it again though: For the KErot: KErot= (1/2)((2/5)(4.3E24kg)(7.6E6m)(2pi/(24hr*60min*60sec))^2 and I got 2.62698301E29 J for the other one...
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    Rotation of a planet, kinetic energy

    so when I plug in my information it will look like this?: (1/2)(4.3E24kg)((2π*1.2E12m)/31557600sec)^2) I get 1.22730571E35. but when I do the ratio, I'm getting the answer wrong.
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    Rotation of a planet, kinetic energy

    am I using the wrong equation to find the kinetic energy of the center of mass for the orbit??
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    Rotation of a planet, kinetic energy

    i'm still getting the wrong answer and I don't know why.
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    Rotation of a planet, kinetic energy

    Why would you square the radius in the second part? because isn't the V=Rw?? so the radius wouldn't be squared?
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    Rotation of a planet, kinetic energy

    Homework Statement Calculate the ratio between the kinetic energy of rotation of a planet (mass=4.30E+24 kg, radius=7.60E+6 m) to the kinetic energy of its center of mass orbiting around its sun at a distance of 1.20E+12 m. Like the Earth, it has a day lasting 24 hours and a year lasting...
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