Recent content by n.hirsch1

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    Calculating Inductance in an RL Circuit

    No, I don't. Its asking for inductance, I have resistance, I have no idea how to get the time constant.
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    Calculating Inductance in an RL Circuit

    Homework Statement An RL circuit has a 9.0 V battery and a 5.5 ohm resistor. When the switch is closed, the current in the circuit is observed to increase from 0 to 0.30 A in 0.17 s. A) What is the inductance? B) How long after the switch is closed does the current have the value 0.47 A...
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    Two batteries and three resistors

    Homework Statement http://session.masteringphysics.com/problemAsset/1122583/1/Walker.21.52.jpg This is the drawing for the problem The two questions are: 1) How much current flows through 6.0 V battery when the switch is closed? 2)How much current flows through 6.0 V battery when the...
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    Calculating Thermal Expansion of a Cookware Pot

    Sorry! I forgot the second part: If the initial temperature of the pot is 23 C, what is the difference in diameter change for the copper and the steel? All I did was plug in the numbers for the coefficient of linear expansion, For stainless steel: L = (17.3 * 10^-6) * (8 in) * (620 C - 23...
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    Calculating Thermal Expansion of a Cookware Pot

    Homework Statement Some cookware has a stainless steel interior (alpha = 17.3 *10^- 6) and a copper bottom (alpha = 17.0 * 10^-6) for better heat distribution. Suppose an 8.0 in. pot of this construction is heated to 620 C on the stove. Homework Equations Delta L = alpha* Lo * delta T...
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    What Power Is Needed To Accelerate An Object To 2.7 rad/s In 5.2 s?

    Homework Statement See the image attached What power must be applied to this object to accelerate it from rest to an angular speed of 2.7 rad/s in 5.2 s about the x axis? Homework Equations P = W / t - torque * angular velocity The Attempt at a Solution P = [(0.5 m)*(7...
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    Find the mass of the merry go round: conservation of angular momentum?

    Once I convert the angular velocity, I can get the correct answer if I multiply it by 2: 2 * [(torque * t) / (angular velocity)] = m*r^2 Why does it work this way and not the other way?
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    Find the mass of the merry go round: conservation of angular momentum?

    Homework Statement A child exerts a tangential 41.6 N force on the rim of a disk-shaped merry-go-round with a radius of 2.40 m. If the merry-go-round starts at rest and acquires an angular speed of 0.0850 rev/s in 3.50 s, what is its mass? Homework Equations torque = r * F (I + mr^2) ω /...
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    Relationship btw volume and temperature of an ideal gas

    Homework Statement The is a piston the is massless and moves with friction A) assuming that out gas is ideal, we will get v = constant T. What are your variables in this case? B) If you plot V vs T on a graph, what is the slop of your graph? C) What is the number of moles for this gas? D)...
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    Calculating Mean Free Path of Molecules in a Test Tube

    Homework Statement A test tube of cylindrical shape having a length of 10 cm and a diameter of 2 cm contains 20 * 10 ^23 molecules (molecular size d = 3 * 10^-10 m). What is the mean free path of these molecules?? Homework Equations λ = 1/ pi * d^2 * n The Attempt at a Solution...
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    Energy conservation: Bullet-block collision

    mgb_phys: I must be looking at the wrong equation. for conservation of momentum, if the final velocity of the system is zero (which it is), and it is an inelastic collision, then the equation is : vf = m1vi +m2vi / m1 + m2 and m2vi is equal to zero since its at rest, so mvi = (m + M) vf and if...
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    Energy conservation: Bullet-block collision

    134 m/s isn't correct either. I don't understand what is wrong with this equation, everything is given. I can't use conservation of momentum for inelastic collisions because I don't have a final velocity.
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    Energy conservation: Bullet-block collision

    Homework Statement A 2.30 g bullet embeds itself in a 1.6 kg block, which is attached to a spring of force constant 770 N/m. A) If the maximum compression of the spring is 5.40 cm, find the initial speed of the bullet. Homework Equations Step one: convert everything to kg and m Step two: 1/2...
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