Recent content by tmobilerocks

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    Do I Need to Include Minus Signs in Energy Conservation Equations?

    In a way. The specific problem deals with a block released above a spring and compressing on it. I define Ug = Us= 0 as the uncompressed point and down as the positive direction. Up is therefore negative, so the block starts out with negative potential energy U = mgh (h is negative). Drawing a...
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    Do I Need to Include Minus Signs in Energy Conservation Equations?

    The block is below the reference point; h is negative. If you do mgh - mgh0 it becomes positive or mgh + mgh0
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    Do I Need to Include Minus Signs in Energy Conservation Equations?

    I drop a block on a spring compressing it. Let's say 0 potential energy is defined at spring equilibrium and down is positive direction. The spring is now compressed. The change in potential energy would be mgh + mgh0 right? (Needed to manually add positive sign to initial potential energy, up...
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    Do I Need to Include Minus Signs in Energy Conservation Equations?

    Hi All, I just have a question regarding potential energies. Say I have a block above a spring, and I define the potential energy of gravity and the spring to be zero at the uncompressed point. I then drop the block, trying to find the maximum compression of the spring using conservation of...
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    What is the Minimum Time for Acceleration in an Auto Engine Power Problem?

    Homework Statement An auto manufacturer reports that the maximum power delivered by the engine of a car of mass 1230 kg is 92.4 kW. Find the minimum time in which the car could accelerate from rest to 29.1 m/s. In a test the time to do this is found to be 12.3 s. Account for the difference in...
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    FBD of Block: Real-Life Example and Equations

    How about a larger block (m3) moving to the left which exerts a normal force on m2. m2 is connected to m1 via a string. m2 and m1 have the right values so they do not move vertically; instead they move at the same acceleration as m3.
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    FBD of Block: Real-Life Example and Equations

    Man still not getting it... can someone please offer specific advice? I understand the principles. It must be accelerating to the left, but I can't think of a real life example.
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    FBD of Block: Real-Life Example and Equations

    Anyone else willing to offer more tips/guidelines to solving this problem?
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    FBD of Block: Real-Life Example and Equations

    Two blocks on table. Second block accelerating to left, exerting a normal force on first block. Person pulls down string on block.
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    FBD of Block: Real-Life Example and Equations

    So what is an example of a real situation?
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    FBD of Block: Real-Life Example and Equations

    Person just let's go off block originally held by hand
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    FBD of Block: Real-Life Example and Equations

    Will accelerate in normal force's direction
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    FBD of Block: Real-Life Example and Equations

    Block at rest on a rough wall. Man pulls the string attached to block to balance with static friction?
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    FBD of Block: Real-Life Example and Equations

    If you push with a horizontal force, canceling the normal force. Problem is I don't think you can add your own force.
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    FBD of Block: Real-Life Example and Equations

    The normal force would come from the surface, say a wall
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