Read about work energy | 11 Discussions | Page 1

  1. Physics lover

    Work done by friction on a two-block system

    I calculated friction = 1N.But since force is more than maximum friction,therefore lower block will not move and a force of 0.5N will be applied to upper block. Therefore its work done by friction will be W=0.5×6=3 J. But answer given is 1 J. Can anyone help.
  2. G

    B Need a bit more clarification on W=F.ds

    I was a bit confused about the work energy theorem. I perfectly understood it's applications for point sized particles but I'm a bit confused about its application on extended bodies both rigid and non rigid. Case 1 {for rigid bodies} :- Consider a rod of definite mass hinged at the top. It's...
  3. S

    I Energy change of reservoir in reversible weight process

    In what follows I refer to the ideas of "Thermodynamic: Foundations and Applications" by Gyftoploulos and Beretta. The abbreviated form of my question is: In a reversible weight process, Ω1R-Ω2R = E1 - E2 (see eqn. 6.18, p. 99) is transferred out of the composite of a system A and a reservoir R...
  4. Jefffff

    Energy and Heat Transfer

    Homework Statement A solar heater is used to warm 150 kg of water by 30 K. The intensity of solar radiation is 6000 Wm-2 and the area of the panels is 4.0 m2. The specific heat capacity of the water is 4.2 * 103 J/kg/K. Estimate the time this will take, assuming a solar panel efficiency of...
  5. V

    Please help me with this mechanics problem -- pulling one end of a spring

    Homework Statement A spring of unstretched length l has a mass m with one end fixed to a rigid support. Assuming spring to be made of a uniform wire, the kinetic energy possessed by it if its free end is pulled with uniform velocity v is? 2. Homework Equations potential energy stored in a...
  6. ElPimiento

    Work that must be done to charge a spherical shell

    1. Calculate the work that must be done on charges brought from infinity to charge a spherical shell of radius R = 0.100 m to a total charge of Q = 125 μC. 2. V = k_e\int{\frac{dq}{r}} \triangle V = - \int{E \cdot ds} W = q\triangle V 3. I started with assuming the spherical shell produces...
  7. W

    Work on 1 pulley system and two masses

    Homework Statement this is from an example problem in the hibbler dynamics book 13th edition in the section of work so i dont really have a question on how to do it. the question is why is the problem solved the way it is solved. the system has one rope.and two masses at each end...
  8. KingDaniel

    How do you derive the pV Work formula, W= "integral"pdV?

    This is a Thermodynamics question. I need help in how to derive the Work done in changing from State 1 and State 2. ie: How do you derive the pV Work formula, W= "integral"dW= "integral"pdV
  9. S

    W=- electric potential

    if w = - change in epe why does power = +epe / time if power is supposed to equal w / t shouldnt it be equal to -EPE / time Please help me clarify this. epe= electric potential energy and also if current equals to Q/t is there a negative current if there is a negative charge? isnt current...
  10. R

    Work done on object vs work done by you

    What is the difference between work done on an object and work done by you? For example, you exert a 100N force pushing a 10kg mass 3.0m across the floor with a coefficient of friction 0.60 1) what is the work done on the mass? 2) what is the work done by you? For question 1 I think it has to...
  11. D

    Atwood Problem

    1. The problem states: Problem 9-72a: The system shown in the figure below consists of a m1 = 4.24-kg block resting on a frictionless horizontal ledge. This block is attached to a string that passes over a pulley, and the other end of the string is attached to a hanging m2 = 2.12-kg block...