Recent content by JenL

  1. J

    Centre of mass

    So if the rope pulls back does that mean it is not moving? Sorry I still do not fully get this
  2. J

    Centre of mass

    Homework Statement a) Two astronauts, A of total mass 90kg and B of total mass 110kg are tied together by a light rope 15m long during a space walk. A starts to reel in the rope at her end. After 8.5s she has reduced the length of the rope by 5.5m. What distance does the centre of mass move in...
  3. J

    Help with electric field problem- Yr 12 physics

    Yes it is the initial kinetic energy that is confusing me. I tried to work it out but the Ep at the anode was less than the Ek gained at the cathode. I know I need to take into consider the initial Ek but I don't understand how it would work.
  4. J

    Help with electric field problem- Yr 12 physics

    Homework Statement Protons are accelerated by an electric field passing through a hole in the anode and accelerated towards the cathode (to the right) A proton passes through the anode at 6.2 × 105 m s–1, and passes through the cathode at 8.8 × 105 m s–1. Show that the strength of the electric...
  5. J

    Help with yr11 magnetic fields

    I asked one of my classmates and is it because in the center there are no magnetic fields lines? (in the diagrams there are no magnetic field lines in the center) so the center's magnetic field strength is 0. I have learnt about vectors in forces but I am not sure if that if the same?
  6. J

    Help with yr11 magnetic fields

    Homework Statement The diagram shows the magnetic field between like magnetic poles Homework Equations Point C is the exact middle of the region between the poles. Explain why the strength of the magnetic field at point C is zero? The Attempt at a Solution The like poles repel each...
  7. J

    Help with yr11 physics please

    Thank you Khemical, that helped. Haruspex, The forces on a ball lying on the ground would be reaction and gravity which would be equal and so balanced. I think I understand the acceleration bit now and the question because wouldn't the acceleration be 10ms^-2 due to the force of gravity. So then...
  8. J

    Help with yr11 physics please

    Fnet= ma, but I do not understand how this equation will relate to the problem because then the acceleration would be 0 at the highest point. So Fnet= 0 meaning forces acting on the ball are balanced and the answer said that the forces are unbalanced.
  9. J

    Help with yr11 physics please

    The question does not say if there is a net force or what forces are acting on the ball
  10. J

    Help with yr11 physics please

    the question doesn't say if there is a net force but the force acting on the ball are gravity and the force from the bat
  11. J

    Help with yr11 physics please

    Homework Statement Jackie's team bats later in the day. When Jacki strikes the ball, she hits it badly and it travels straight up. Homework Equations Explain whether the forces are balanced or unbalanced at the highest point. The Attempt at a Solution I thought it was balanced as the...
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