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      1. A bug of mass 20 mg sits near the edge of a long play (LP) record, at a distance 15 cmfrom the centre. The record player is turned on and the record brought up to its
        normal speed of rpm (rev/min). Calculate the minimum value of the coefficientof friction between the bug and the record if the bug does not slip off the record.
        Total Marks [9]

      2. A truck of total mass 2000 kg travelling at a speed of 15 ms-1, goes over an archedbridge which has a radius of curvature equal to 25 m. Calculate:
        1. a) The contact force on the truck when the truck is at the top of the arch. [6]
        2. b) The maximum speed at which the truck could safely pass over the bridge, such
          that it just loses contact with the road. [4]Total Marks [10]


      3.
      a) Starting from Newton’s Law of Universal Gravitation show that the orbital period
      of a satellite of mass , at a distance from the centre of a planet of mass isgiven by:
      where is the universal gravitational constant. [6]b) Use the following data for Mars and Phobos, one of the Moons of Mars, to
      calculate:

      1. i) the orbital period of Phobos, giving your answer in hours. [6]
      2. ii) the escape velocity from Phobos. [3]
        Radius of Mars = 3 390 kmMass of Mars = 6.4169 x 1023 kg
        Mean radius of Phobos = 11.1 km
        Mass of Phobos = 1.0659 x 1016 kg
        Mean orbital height above the Martian surface = 5 987 km
        Total Marks [15]


      4. A spring is stretched 4cm when a mass of 50g is hung on to it. A total mass of 150gis now hung on the end of the spring and displaced so that it performs small verticaloscillations. Calculate the period of these oscillations.
      Total Marks [8]







    I've got so far with each question but then end up stuck at some point or another, could anyone offer any help/tips please? Thanks
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    Welcome to TSR physics.

    Show us how far you've got and at what point you are stuck.
    We can't help you if you don't tell us what help you need.

    What equations do you know that relate to circular motion?
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    (Original post by Stonebridge)
    Welcome to TSR physics.

    Show us how far you've got and at what point you are stuck.
    We can't help you if you don't tell us what help you need.

    What equations do you know that relate to circular motion?
    I know the formulas for angular displacement, angular velocity and centripetal force
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    So let's look at Q2

    How far have you got with that one using the idea of the centripetal force on the truck?
    Where are you stuck?
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    (Original post by Stonebridge)
    So let's look at Q2

    How far have you got with that one using the idea of the centripetal force on the truck?
    Where are you stuck?
    I have completed part a and obtained an answer of 1620N.
    mv^2/r = mg - R
    R = mg - mv^2/r
    R = (2000 x 9.81) - (2000x15^2 / 25) = 1620N

    Is this correct?
    I am struggling with part b and not really sure how to go about it
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    (Original post by rjnknr)
    I am struggling with part b and not really sure how to go about it

    At the point where it's just about to come off, Fc = weight

    Equate the equations and solve for v
 
 
 
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