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    Orbit Problem

    Homework Statement Two moons orbit a planet in nearly circular orbits. Moon A has orbital radius r, and moon B has orbital radius 5r. Moon A takes 50 days to complete one orbit. How long does it take moon B to complete and orbit? Homework Equations Kepler's Third Law The...
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    Angular Acceleration

    So, I do that and I get .839. I kept 8.5 as my theta. It still isn't right. What could I be doing wrong?
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    Angular Acceleration

    Homework Statement A cyclist starts from rest and pedals so that the wheels make 8.5 revolutions in the first 4.5 s. What is the angular acceleration of the wheels (assumed constant)? Homework Equations \alpha = \Delta\omega/ \Deltat The Attempt at a Solution I converted...
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    Block on Horizontal Table

    Homework Statement A small block of mass 0.91 kg slides without friction on a horizontal table. Initially it moves in a circle of radius r0 = 0.63 m with a speed 1.5 m/s. It is held in its path by a string that passes through a small hole at the center of the circle. The string is then...
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    Skater Rate of Rotation

    I still don't really understand
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    Skater Rate of Rotation

    Homework Statement A figure skater is spinning at a rate of 2 rev/s with her arms outstretched. She then draws her arms in to her chest, reducing her rotational inertia to 61% of its original value. What is her new rate of rotation? Homework Equations ? The Attempt at a...
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    Change in Pressure

    If I change 4 cm to meters I get 58800 as the calculated total from the equation, which is incorrect according to the website. Is there some factor I'm neglecting?
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    Change in Pressure

    Homework Statement An experiment to determine the specific heat of a gas makes use of a water manometer attached to a flask (the figure below ). Initially the two columns of water are even. Atmospheric pressure is 1.5 105 Pa. After heating the gas, the water levels change to those shown...
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    Water Pressure in a lake

    Homework Statement At the surface of a freshwater lake the pressure is 106 kPa. (a) What is the pressure increase in going 34.5 m below the surface? (b) What is the approximate pressure decrease in going 36 m above the surface? Air at 20°C has density of 1.2 kg/m3. Homework Equations...