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I have a lot of problems please help!

  1. Jan 13, 2010 #1
    When a person stands on rotating merry-go-round, the frictional force exerted on the person by the merry-go-round is:
    a.greater in magnitude than the frictional force exerted on the merry-go-round by the person
    b. opposite in direction to the frictional force exerted on the merry-go-round by the person
    c. directed away from the center of the merry-go-round
    d zero if the rate of rotation is constant
    e. independent of the person's mass

    I'm pretty sure it is b or c

    2. Each of the five satellites makes a circular orbit about an object that is much more massive than any of the satellites. The mass and orbital radius of each satellite are given below. Which satellite has the greatest speed?
    Mass Radius
    a. 1/2m R
    b. m 1/2R
    c. m R
    d. m 2R
    e. 2m R

    I was thinking D because mv^2/r^2 is the equation so you want a big m and a small r to get the greatest v.

    3. A ball attached to a string is whirled around at speed v in a horizontal circle having a radius r. if the radius of the circle is changed to 4R and the same centripetal force is applied by the string, the new speed of the ball is:
    a. 1/4v
    b. 1/2v
    c. v
    d. 2v
    e. 4v

    IDK how to even start this one mv^2/r^2 I'm thinking maybe 1/4 A
    4. Two planets have the same size, but different masses, and no atmospheres. Which of the following would be the same for identical 1kg objects on the frictionless surfaces of the two planets?

    I The rate at which each would fall freely
    II The amount of mass each would balance on a double pan balance
    III The amount of acceleration each would have when a certain horizontal force is applied

    a. I only
    b. III only
    c. I and II only
    d. II and III only
    e. I, II, and III
     
    Last edited: Jan 13, 2010
  2. jcsd
  3. Jan 13, 2010 #2

    ideasrule

    User Avatar
    Homework Helper

    You MUST show relevant equations and an attempt at a solution.
     
  4. Jan 13, 2010 #3
    alright
     
  5. Jan 14, 2010 #4
    Sorry about not showing my thought process before but these are optional review problems that I would like to have done before my test Monday just to understand better.I do NOT have to hand them in.
     
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