Recent content by abelthayil

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    The Standard Deviation of a Brownian Force

    I'm trying to understand the derivation of the expression for the random Brownian force on a particle in a medium with coefficient of viscosity η. It turns out it is gaussian over some timescale, with a standard deviation that depends on the temperature and the viscosity. I'd like to read a...
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    Atmosphere Modeling: If G Doubles, How Tall?

    If g (acceleration due to gravity) was double on Earth, how tall would our atmosphere be?
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    Direction of frictional force in a bicycle

    Oh right! Frictional force has nothing to do with speed but isn't the coefficient of friction equal for the two tires? I assumed that the normal force on both tires would be equal. I guess it isn't. So does that mean the position of the seat determines how easy it is to cycle?(to overcome the...
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    Direction of frictional force in a bicycle

    As soon as the back tire moves even a little, the front tire has to move as well. Since both tires move at the same speed and are made of the same material, the frictional force on the tires is equal and opposite. So where is the force that is pushing the cycle forward??
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    Electrostatics -Electric Field and Potential

    Oh YES ! How silly of me Thanks !
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    Electrostatics -Electric Field and Potential

    Homework Statement A 30 cm diameter metal sphere hangs from a thread in the middle of a very large room. So its surroundings are essentially at infinity. If the electric field at tis surface is equal to the break down strength of air 3MV/m, what is the absolute potential at the center of the...
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    The frequency(/time period) of oscillation for a 2 body spring system

    Homework Statement Two masses m1 and m2 are connected by a spring of spring constant k rest on a frictionless surface. If the masses are pulled apart and let go, the time period of oscillation is : I know the answer is T(time period) = 2∏\sqrt{((m1*m2)/(m1+m2))*1/k}. Can some one help me...
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    If sound travels faster through solids then why can't we hear through doors?

    Why can't sound pass through closed doors?
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