Physics Please help!

Calculate the position of the center of mass of the following pairs of objects. Use acoordinate system where the origin is at the center of the more massive object. Give youranswer not in meters but as a fraction of the radius as requested. Get data from insidethe front cover of your text.

Earth Radius = 6.37x10^6 m

Moon Radius = 1.74x10^6 m

Jupiter Radius = 1.90x10^7 m

Earth to moon distance = 3.84x10^8 m

earth to sun 1.496x10^11m

jupiter to sun 7.78x10^11 m

(a) The Earth and the Moon. Give the answer as a fraction of the earth's radius.

(b) The Sun and the Earth. Give the answer as a fraction of the sun's radius.

(c) The Sun and Jupiter. Give the answer as a fraction of the sun's radius.

please show how to get it i am really stuck.

  1. 👍 0
  2. 👎 0
  3. 👁 994
  1. Just think of the planets as point masses on a lever. We want the lever to balance, where the fulcrum is the center of mass.

    So, m1d1 = m2d2
    or, m1/m2 = d2/d1

    For earth-moon,
    d = 3.84x10^8 = d1+d2
    earth mass = 5.9742x10^24
    moon mass = 7.3477x10^22

    m1/m2 = 81.307
    so, 82.307 * d1 = 3.84x10^8
    d1 = 4.7228x10^6

    So, the center of mass for the earth-moon system is 4.7228x10^6m from the center of the earth.

    4.7228x10^6/3.84x10^8 = 0.0123 of earth radius

    do similar work for the other systems

    1. 👍 1
    2. 👎 0
  2. Oops. I figured as a fraction of the earth-moon distance, not the earth radius.

    4.7228x10^6/6.37x10^6 = 0.74 of earth radius

    1. 👍 1
    2. 👎 1

Respond to this Question

First Name

Your Response

Similar Questions

  1. Physics

    The mass of a star in a galaxy far, far away, is 2.13 × 105 Earth masses, and the mean distance from the center of this star to the center of a planet with the same mass as our Earth is 7.87 × 108 km. Treating this planet and

    asked by Briana on January 17, 2016
  2. physics

    For the purposes of this problem, there are three parts to the figure, and the center of mass of each one is shown in the drawing. These parts are: (1) the torso, neck, and head (total mass = 40.4 kg) with a center of mass located

    asked by Anonymous on March 27, 2014
  3. Physics

    Three objects are connected as shown in the figure below. They move along a horizontal, frictionless surface, and are pulled to the right with a force Fext = 1.3 N. With the three mass values given as m1 = 726 g, m2 = 633 g, and

    asked by Sam on October 2, 2009
  4. science

    Two forces, of magnitudes F_1 = 85.0 N and F_2 = 45.0 N, act in opposite directions on a block, which sits atop a frictionless surface, as shown in the figure. Initially, the center of the block is at position x_i = -4.00 cm. At

    asked by BRIJ on November 23, 2010
  5. Physics

    A person with mass m1 = 57 kg stands at the left end of a uniform beam with mass m2 = 92 kg and a length L = 2.7 m. Another person with mass m3 = 67 kg stands on the far right end of the beam and holds a medicine ball with mass m4

    asked by MUHAMMAD JUNAID on April 3, 2019
  1. physics

    consider 4 masses mA=1kg, mB=2kg, mC=3kg, mD=4kg, placed at the vertices of a square ABCD of side 4cm. Specify the position of G the center of mass of the system{A,B,C,D}. determine the position of G. Thank you :)

    asked by anna on January 3, 2011
  2. physics

    A long thin rod lies along the x-axis from the origin to x=L, with L= 0.890 m. The mass per unit length, λ (in kg/m) varies according to the equation λ = λ0 (1+1.410x2). The value of λ0 is 0.700 kg/m and x is in meters. 1.

    asked by Naya on February 12, 2014
  3. Physics

    Calculate the position of the center of mass of the following pairs of objects. Use a coordinate system where the origin is at the center of the more massive object. Give your answer not in meters but as a fraction of the radius

    asked by Lindsay on December 15, 2011
  4. physics

    A jumper of mass m=55 kg starts in a crouched position with the jumper's center of mass at a position y1=0 m. Just before the jumper leaves the floor, his or her center of mass is at y2=0.7 m. From another measurement, you have

    asked by Zoey on July 26, 2014
  5. Physics

    A light, ideal spring with a spring constant k = 100 N/m and uncompressed length L = 0.30 m is mounted to the fixed end of a frictionless plane inclined at an angle θ = 30.0° as shown above. Then a mass M 0.300 kg is affixed to

    asked by Jonah on October 22, 2017

You can view more similar questions or ask a new question.