Recent content by peaches1221

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    Thermodynamics (Carnot Engines)

    1. The amount of heat that an engine rejects to the cold reservoir is 3 times the amount of work that it does. What is the efficiency of the engine? e = W/ Qh = 1 - Qc/Qh For this problem, I said e= w/3w. Thus e would equal 1/3 = 0.333. This however is not correct. What did I do wrong...
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    Help Me Solve My Problems: U-Tube and Styrofoam Bucket

    I really suck at these problems. I don't know what I'm doing wrong. Please help. 1. A U-tube contains liquid of unknown density. An oil of density 785 kg/m3 is poured into one arm of the tube until the oil column is 15 cm high. The oil-air interface is then 7 cm above the liquid level in the...
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    Calculating Impact Speed and Mass of Ice Cube: Temperature/Heat Help

    thank you so much. i have to read these problems more carefully.
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    Calculating Impact Speed and Mass of Ice Cube: Temperature/Heat Help

    Thank you so much for your help on the first problem. I overlooked the fact that I had to take into account the phase change. However, I'm still confused on the second problem. The equation I originally had should be this: Mice*Cice(10) + MiceLf + MiceCw(25)= MiceCw(25-11) + MalCal(25-11)...
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    Calculating Impact Speed and Mass of Ice Cube: Temperature/Heat Help

    Thank you so much for your help on the first problem. I overlooked the fact that I had to take into account the phase change. However, I'm still confused on the second problem. The equation I originally had should be this: Mice*Cice(10) + MiceLf + MiceCw(25)= MiceCw(25-11) + MalCal(25-11)...
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    Calculating Impact Speed and Mass of Ice Cube: Temperature/Heat Help

    I have two questions that I need help with. Any help will be appreciated. 1. A lead bullet initially at 17oC just melts upon striking a target. Assuming that all of the initial kinetic energy of the bullet goes into the internal energy of the bullet to raise its temperature and melt it...
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    Simple Harmonic Motion of a gun

    Yeah, I'm an idiot. Thanks for your help.
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    Simple Harmonic Motion of a gun

    Thank you both for your help. I'm still not sure if I completely understand this problem PE= 1/2kx^2 where I know k because it is 416 N/M and X=.18. so I would solve for the PE. Then you're saying if the spring energy is converted to kinetic energy, then is KE=PE? thus KE= 1/2mv^2 and...
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    Simple Harmonic Motion of a gun

    (1)It takes a force of 75 N to compress the spring of a toy popgun 0.18 m to "load" a 0.14 kg ball. With what speed will the ball leave the gun? I used the equation F=kx I solved for K and I got 416 N/m Then I used the equation omega = square root(K/M) I solved for omega and i got 54.5...
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    Elasticity and simple harmonic motion

    A mass sitting on a horizontal, frictionless surface is attached to one end of a spring; the other end is fixed to a wall. 3 J of work is required to compress the spring by 0.12 m. If the mass is released from rest with the spring compressed 0.12 m, it experiences a maximum acceleration of 19...
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    Work & Energy for a Roller Coaster

    thank you all for your help!
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    Work & Energy for a Roller Coaster

    thank you all for your responses. I looked back at this problem and looked again at the forces affecting the object, the normal force, the weight, and friction. Please tell me if I'm going in the right track. If I find the net work, that would be delta KE. Then I would just have to solve for the...
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    Work & Energy for a Roller Coaster

    [SOLVED] Work and Energy Hello, I'm a little new to this forum but I would really appreciate some help with this particular problem. A roller coaster reaches the top of the steepest hill with a speed of 5.8 km/h. It then descends the hill, which is at an average angle of 25 degrees and is...
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