Search results

  1. L

    Mechanical advantage machines

    I've been at this problem for a good hour now and I just can't figure it out :bugeye: Please help me think through this! It is a very difficult problem in my opinion. Or maybe I'm just missing a fundamental point...Thanks in advance...
  2. L

    RC Circuits, capacitor charges and voltages

    These are 2 stand alone problems, however the answers disagree with one another and I am trying to reconcile their differences. Any insight would be appreciated! :) The answer is C. The answer provided with this question is that "there is no dependence on resistance of any kind". However the...
  3. L

    Conducting bar on a rail question

    Disclaimer: this question is really just for my own edification in preparation for a test. In the figure above, we have a conducting bar that is placed onto two sloped conducting rails. The box labeled V is a voltage source. Lastly there is a magnetic field starting from the "base", rising up...
  4. L

    Conducting bar in a uniform magnetic field

    I'm studying for the MCAT and this problem came up. The correct answer is D. However the explanation was very confusing. The explanation is verbatim: " Let's start by considering A. Using the right-hand rule on a current running through the wire in figure 2 shows you that the rod is pushed...
  5. L

    Capillary action

    How is B more correct than D? Both show that forces between glass and fluid are stronger than those between fluid molecules. Thank you for any insight!
  6. L

    Ideal fluids, bernouilli's law

    I do not understand why B is not true. There is much greater fluid molecules above point A, and given P = density x g x depth, pressure should be greater at point A.....making B true. But then again if u use poiseuilles' law for nonideal fluids you see that in order to keep flow rate Q constant...
  7. L

    Interpretation of an impulse graph

    Which of the following is true if the mass is at rest at t=0 ? A. Velocity of the mass is decreasing btwn 10 and 20 seconds. B. The accel. of the mass is constant between 0 and 10 seconds C. At 40 seconds the mass is stationary. D. The distance trsveled by the mass bten 0 and 10 seconds is...
  8. L

    Work, forces on inclined plane

    W = fd The answer is 8. The solution manual says work is the same for either scenario, d = 4 or d = 0.5 From this assumption I can see that by increasing distance from 0.5 to 4, you reduce the force necessary by a factor of 8. However what I cannot comprehend is: where does the assumption...
  9. L

    Energy generated by proton-proton cycle

    [b] My attempt [b] Q Reaction 1: Q1 = 2(1.007825) - (2.014102 + 0.000549) = 9.99E-4 u Q Reaction 2: Q2 = 1.007825 + 2.014102 - 4.002603 = -0.980676 u Q Reaction 3: Q3 = 3.016030 - (4.002603 + 2(1.007825)) = 0.013807 u --------- 2(Q1) + 2(Q2) + Q3 = -1.945547 u (-1.945547...
  10. L

    Nuclear physics: critical state and fission

    When a nuclear reactor is in a critical state, the neutrons released in each fission trigger an average of exactly one additional fission. If the average number of additional fissions triggered rises above one, the reactor enters a supercritical state in which the fission rate and the thermal...
  11. L

    Interference and wave nature of light

    Two in-phase sources of waves are separated by a distance of 4.00 m. These sources produce identical waves that have a wavelength of 5.00 m. On the line between them, there are two places at which the same type of interference occurs. Where are the places located? I already know the...
  12. L

    Electromagnetic waves, doppler effect

    I pay for chegg to help me with physics but sometimes I'm not quite sure if the site is right. Could you please tell me if I am doing the below problem correctly? My way is different than Chegg's so I would just like to make sure I am not wrong because I am getting different answer than that...
  13. L

    Simple magnetic flux question

    1. A loop of wire has the shape shown in the drawing. The top part of the wire is bent into a semicircle of radius . The normal to the plane of the loop is parallel to a constant magnetic field of magnitude 0.75 T. What is the change in the magnetic flux that passes through the loop when...
  14. L

    Simple magnetic fields problem

    One component of a magnetic field has a magnitude of 0.0266 T and points along the +x axis, while the other component has a magnitude of 0.0648 T and points along the -y axis. A particle carrying a charge of +2.96 × 10-5 C is moving along the +z axis at a speed of 4.71 × 103 m/s. (a) Find the...
  15. L

    Simple electrostatic fields questions

    Imagine nine vertical and parallel lines drawn side by side. They represent infinite planes of uniform voltage. The first line has 0 V. The 2nd line has 1 V. The 3rd has 2 V and so on, with the 9th line having 8 V. The distance between each line is 1 cm, which is 0.01 meter. There is an...