1. bravopipo

    Spring related problem, force time mass and displacement

    Hello, Kindly solve this problem for me, or at least give me the procedure of equation to use. I don't know how to begin because I have not found any relationship that relate spring constant to time. If you find the solution, give me numerical result. We have (see the picture): 1. A...
  2. S

    Why Use So Small A Mass For The A-Bomb

    I am going to offer my rudimentary understanding of E=mc2. I have always taken that equation to mean that massive amount of Energy can be gleaned from even the smallest amount of mass. If that simplistic view is correct, then I want to raise a question: If great Energy can be obtained...
  3. P

    Do all object really fall at the same rate regardless of mass?

    Ive always had this question in the back of my mind? Do all objects fall at the same rate regardless of mass? This theory has been tested many times. I just watched a video on youtube where they dropped a bowling ball and a feather at the same time in a giant vacuum chamber. As predicted, they...
  4. C

    Help calculating power required to lift a mass

    Hello, I realize that this is a Physics 101 pop quiz problem, but it's been 45 years since I was in Physics 101 I'm trying to figure out what size of a 12VDC motor to purchase to perform the following work. I have a 40 Kg tool that I want to lift 30cm within 60 seconds. If you need the length...
  5. C

    Mass of a box been pushed taking friction into account.

    This feels like a really basic question so i feel like I'm making an assumption that I shouldn't be. Max fs=us*N Fk=uk*N N=mg For the box to start to move Fk must equal Fs. So I can rearrange for m from there us*75*9.81=uk*9.81*m but this answer isn't ending up anywhere near the correct answer...
  6. S

    Calculate the mass deficit in this nuclear reaction

    Calculate the mass deficit in this nuclear reaction $12{\rm C}+\frac{12}{6}{\rm C}\rightarrow \frac{24}{12}{\rm Mg}$ Information given: - rest mass of a carbon-12 nucleus: $1.9921157\times 10^{-26}\,{\rm kg}$ - rest mass of a magnesium nucleus: $3.9817469\times 10^{-26}\,{\rm kg}$ -...
  7. A

    How much mass needed to cool down liquid? It's question 5. Could someone push me in the right direction here. Idk what's up. Is there a part along the way where I've got it wrong or is it right from the beginning lol? Thanks for any help (Bigsmile)
  8. G

    Basic Question - Mass vs Weight

    My daughter had a question from school and it confused me. The question reads: True of False; Both weight and mass measure how heavy (or light) an object or a substance is. My daughter circled false and I agree with her. But she missed that question. Mass is different than weight. Weight...
  9. A

    Given tension, mass, length, find the mass

    "The string on a conical pendulum is 2m in length an has a tension on the string holding the object has a mass of 100 N. The radius of motion is 0.4 m and the period of rotation is 2 seconds. What is the mass of the object?" Does anybody have any resources to help solve this problem?
  10. E

    Measuring the distribution of mass in a solid object

    I am interested in measuring the distribution of mass in a solid object, specifically a tennis racket. Is there a simple way to do this? I only need to know the approximate distribution of mass along the length of the racket, which is 68.5 cm. So, for example, I could cut the racket into...
  11. A

    Question about mass/spring system

    Using the energy method. What is the relation between δmax and δst? a) δmax = δst b) δmax = 1/2 δst c) δmax = 2 δst d) δmax = square(2) δst
  12. avito009

    Energy mass conversion in microwaves.

    As we know when the electrons are excited they move from higher energy state to ground state causing electromagnetic radiation. Now EM radiation in form of microwaves is Energy. Where has this energy come from. From the mass of the electron?
  13. O

    Could a large Coronal Mass Ejection shift Earth's rotational axis

    Very strong rumours that an explosive CME is about to happen within a few years ..... Corey Goode was shown a simulation , by friendly ETs , of what we can expect ... There is a massive release of plasma by the sun , centered mainly around the sun's equator , on Earth an observable change...
  14. K

    How To Measure The Mass And Balance Point Of A Human Limb?

    Preferably the forearm. I can't spend big money on x-rays, nor can I chop my arm off. I've asked this elsewhere - LINK I know the volume of my forearm, using the Archimedes method, for 10 equal segments of my forearm. I've also looked at x-rays to work out roughly tissue distribution...
  15. T

    Water heater and mass flowrate

    Hello everybody! I was thinking: if I change the mass flow rate (by opening the tap when I'm going to take a shower) the water will take more or less time to heat? I've proceeded as follows: by making the heater my control volume: \dot{Q}=\frac{d(nU)}{dt} + \dot{n}(H^{out}-H^{in})...
  16. H

    tha mass of photon,a topic of both old and new

    the mass of a photon ,either the static mass is M0 and the released mass is ∞,or the released mass is hγ and the static mass is zero, (the detailed calculation with Special Relativity omitted),but both are meaningless in physics. If photon has no effective mass, how to explain the Campton...
  17. avito009

    Why is mass uncertain in case of Heisenberg Principle?

    I read that for Higgs Boson Heisenberg Uncertainty Principle applies. But why is mass uncertain in case of short lived unstable particle? That being said the momentum is uncertain which tells us that the position is known. Is the position known by measuring the Higgs Bump? Is the velocity also...
  18. V

    Mass resting on another mass

    Figure 3 depicts a mass (A) of 20 kg resting on another mass (B) of 100kg. Mass B rolls without friction over the ground, but the interface between the masses is rough, μ=0.5. Determine the accelerations of the masses if the force P in the cable is: (i) 60 N, (ii) 40 N...
  19. H

    What effect does increasing or decreasing mass of a trolley have on my value of g?

    My guess is that as f=ma if mass decreases and force is equal then acceleration increases, but this seems wrong. Could someone please help and let me know what effect increasing or decreasing that mass of a trolley rolling down a ramp will have on my value of g ( acceleration due to gravity ) ...
  20. O

    Active mass

    Good idea Dan ..... Deep breath .... Dear friends .... I have seen in literature the terms "active gravitational mass" and "passive gravitational mass" , here's a quote ... "We might distinguish two kinds of gravitational mass, active and passive. The active gravitational mass is the...