Recent content by lostie100

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    Gravitational field, density and mass.

    F = Gm1m2/r^2 but doubling the mass doesn't double the force.
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    Gravitational field, density and mass.

    A satellite orbits a planet. The gravitational field strength at the radius of the orbit is 12 N/kg. What will the gravitational field strength at the position of the satellite be if - The planet's density is doubled? - The satellite's mass is doubled? I just don't understand their...
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    Frustrated with Physics: Measuring Temperature Changes in the Ocean

    Ok. At a depth of 1000m, the ocean temp is 4 degrees celsius and the speed of sound is 1480m/s. From lab experiments, for every 4m/s increase in velocity, the temp increases by 1 degrees. When the distance is 8000km, the smallest time change that can be detected is 1s, what is the smallest...
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    Velocity of Wave in Twice the Radius String: V = root(Tension/mu) * root2

    The mass also doubles...but I don't see how it relates to the other formula for velocity...
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    What are its wavelength and frequency?

    A wave travels with speed 200m/s. Its wave number is 1.5rad/m. What are its wavelength and frequency? distance = wavelength x # of wavelengths v=lamda(f) 1m = 1.5 (lamda) since in 1 meter there was 1.5 waves. 1/1.5 = 0.66m 200 = 0.66 (f); f = 300Hz. But this is wrong. I don't know...
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    Velocity of Wave in Twice the Radius String: V = root(Tension/mu) * root2

    A wave travels along a string at a speed of 280m/s. What will the speed if the string is replaced by one made of the same material and under the same tension but having twice the radius? V = root (Tension/mu) mu = mass/length length is 2radii I manipulated the formulas, however...
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    What is the astronaut's speed when the spring's length is 1.2?

    Thank you very much! Also, how do you determine the sign of the velocity? It doesn't say whether it is going forward or backward...
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    What is the astronaut's speed when the spring's length is 1.2?

    ohhh x should be 1.2-1.0=0.2m http://session.masteringphysics.com/problemAsset/1001073/10/knight_Figure_14_36.jpg Can you explain to me what the length from 0 to 0.6m is for? Is that the part that is not stretched at all?
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    What is the astronaut's speed when the spring's length is 1.2?

    I used (1/2)mv^2 + 1/2kx^2 = 1/2k(A)^2 since at the length 1.2m, the total energy in the system should equal the potential energy at the amplitudes. So, I just plugged in 54.7kg as m, 240 as k and 0.4m as amplitude and 1.2m as x. The amplitude concerns me because if I use x(0) = Acos(theta)...
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    What is the astronaut's speed when the spring's length is 1.2?

    Hmm right. I thought it was constant for some reason. I know it's not. Okay, I'm not getting the right answer though...The diagram is shaped like a W with the highest point at 1.4m and lowest point at 0.6m. Lasts for 6 seconds...2 oscillations...
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    What is the astronaut's speed when the spring's length is 1.2?

    But how can a velocity of -2.37m make sense if the minimum distance from the equilibrium is 0.6m and that 1 oscillation takes less than a second?
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    What is the astronaut's speed when the spring's length is 1.2?

    Astronauts in space cannot weigh themselves by standing on a bathroom scale. Instead, they determine their mass by oscillating on a large spring. Suppose an astronaut attaches one end of a large spring to her belt and the other end to a hook on the wall of the space capsule. A fellow astronaut...
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    Which Radians to Use in Calculating Phase Constants?

    I just have a simple question as to which radians to use in calculating phase constants in oscillations. For example in sin(theta) = 1/2, do I use the (pi)/6 or 5(pi)/6? The exact question has a diagram and is difficult to explain, but I just want a general explanation. Thank you!
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    Maximum oscillation amplitude for block

    I don't quite understand this problem. I know the formulas to use, but I'm confused as to which mass I should use in the w=root (k/m) equation. Also, the force of friction is around 4.9N, would that also be the block's acceleration? what would that do?
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