Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Forces & Fields HELP

  1. Feb 11, 2007 #1
    1. The problem statement, all variables and given/known data

    Forces & Fields
    Calculate the acceleration of the earth in its orbit around the sun and the net force exerted on the Earth.what exerts this force on the earth? Assume that the Earth's Orbit is a circle of radius 1.49*10^11m.
    2. Relevant equations
    1 year=3.16*10^7
    mass of the earth = 5.98*10^24kg
    radius of the earth = 6.37*10^6m.
    3. The attempt at a solution
    I was approaching the question by using the equ. v2(v squared)/r.
    but velocity is unknown and the distance between the sun and the earth.:confused:
  2. jcsd
  3. Feb 11, 2007 #2
    It's easy to find the speed--it's just distance per unit time.
  4. Feb 11, 2007 #3


    User Avatar
    Staff Emeritus
    Science Advisor

    Consider that the magnitude of average velocity (i.e. speed) can be taken as the quotient of distance travelled (orbital circumference) divided by the time (orbital period).
  5. Feb 11, 2007 #4
    But neither the radius or the diameter was was given :| i wa thinking along that line but we dont have that information. is there any other way or is that the only way?
  6. Feb 11, 2007 #5


    User Avatar
    Homework Helper

    In your question you wrote:

    "Assume that the Earth's Orbit is a circle of radius 1.49*10^11m."

    That's your distance between the sun and the earth.
  7. Feb 11, 2007 #6
    oooooh wow it was right infront of me thanx hage567
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook