Ask Me Help Desk

Ask Me Help Desk (https://www.askmehelpdesk.com/forum.php)
-   Physics (https://www.askmehelpdesk.com/forumdisplay.php?f=258)
-   -   Force of Gravity (https://www.askmehelpdesk.com/showthread.php?t=532832)

  • Dec 8, 2010, 01:09 PM
    susus
    Force of Gravity
    I'm done with the first 1 and 2
    I have problem with 3
    1)
    Calculate, using Newton's law of gravity, the size of the force of attraction between the Earth and a mass of 3.0 kg on the Earth. Data: Distance to the center of Earth from the surface = 6370 km. Mass of Earth = 5.98 1024 kg. Gravitational constant (G = 6.67 times 10−11 Nm2/kg2).
    (in N) 2.949×101 N

    2)
    Calculate, using Newton's law of gravity, the size of the force of attraction between the moon and a mass of 3.0 kg on the earth surface nearest the moon. Data: Distance to the moon from surface of the earth = 376,000 km. Mass of moon = 7.36 times 1022 kg.
    (in N) 1.042×10-4 N

    3) Calculate, using Newton's law of gravity, the ratio of the strength of the force of attraction of a mass of 3.0 kg on the earth's surface by the sun to that by the moon. Additional Data: Mass of sun =1.99 times 1030 kg. Distance from the sun to the surface of Earth = 1.50 times 108 km.
    OK what I did here is this
    of course I use
    F= G*m1*m2/r^2
    G= 6.67*10^-11
    m1 sun = 1.99*10^30 kg
    m2 = 3 kg
    r (d from sun to eath ) = 1.50*10^11 m
    I put the stuff I have in the law..
    and I got 0.0176 N and it's not right..
    well here they ask us.. from moon to sun, so I guess my problem was there ?
  • Dec 9, 2010, 12:19 AM
    Unknown008

    So far so good. You just didn't answer what the question was asking for.

    Quote:

    Calculate, using Newton's law of gravity, the ratio of the strength of the force of attraction of a mass of 3.0 kg on the earth's surface by the sun to that by the moon.
    I got 170 rounded to 3 sf. :)
  • Dec 9, 2010, 06:33 AM
    susus
    Comment on Unknown008's post
    well yeah , I now got the question .
    OK this is what they need
    F of the sun (in these question ) / F of the moon (in these question) = the ratio..
    but , I did it and I got it also wrong !
  • Dec 9, 2010, 06:43 AM
    Unknown008

    Could you post what you did? Maybe we'll spot your mistake :)

  • All times are GMT -7. The time now is 05:13 AM.