Recent content by neo982

Thanks for all your help. I have a really good grasp on it now.

so do I need to make the eq 2*K_f +U_f = U_i with the r's 1.3x10^11 and 2*6.99x10^7 or make them ... half of 1.3x10^11 and the other just 6.99x10^7 ? well...I i know i get the right answer from using 1.3x10^11 and (2*6.99x^10^7) but what is the reason to use the diameter instead of...

Im not sure if I follow you...what would the v_f eq look like..?

well if you solve 1/2mv^2 + (-Gm1m2/r_f) = (-Gm1m2/r_i) for velocity you get that (-1/r +1/r) part so they are not opposite signs, but anyway...so the initial r would be half of the distance given which is 1/2 (1.3x10^11) = 6.5x10^10 right...if this is true then I am not sure what would be the...

Homework Statement Two Jupiter-size planets are released from rest 1.30×10^11 m apart. What are their speeds as they crash together? Homework Equations The Attempt at a Solution I have done K_f + U_f = K_i + U_i with K_i being zero because they have crashed together so... K_f + U_f = U_i...

Thanks I got it.. K_f + U_f = 0 ..therefore v_f = sqrt([2*G(2*mass of planet)/r]) where radius is 1/2 of the value the question gives..which is the diameter...which is 32,586 m/s Thanks.

Homework Statement A binary star system has two stars, each with the same mass as our sun, separated by 1.00×10^12 m. A comet is very far away and essentially at rest. Slowly but surely, gravity pulls the comet toward the stars. Suppose the comet travels along a straight line that passes...