Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.

Calculating Acceleration + Speed of Particles (Gravity Unit)?

Deep in space, away from all bodies, a mass of 100kg is placed at (0,0) and another mass of 100kg is placed at (0,1). These two masses are fixed. A pea which is free to move is placed at (1,0) and released from rest.

a) What is its acceleration? [ANSWER GIVEN: -9.03 i hat + 2.36 j hat nm/s^2]

b) Assuming it passes through the point (0, 1/4), what is its speed at that point? [0.22 mm/s]

I am lost on this lol. I got taught this in one hour and now I have a quiz on monday? I have the answer given to me, but I'm unsure how to do the work. The closest equation in my notes is

F = G(mass 1)(mass 2)(radius from 1 to 2) / (radius from 1 to 2 )^3 so I could calculate F from pea to object 1 + F from pea to object 2 to get Fnet. Then acceleration is Fnet / mass of pea??

I wasn't able to work this out myself, and would appreciate help.

1 Answer

Relevance
  • 3 years ago

    You have masses in kg, but your distances have no units. Also the mass of the pea is missing, but I think that cancels out.

    when you get the units for the distance, use the equation below, treating F as a vector. Calculate the two forces and add as vectors. Then use F = ma, with a being a vector.

    Gravitational attraction in newtons

    F = G m₁m₂/r²

    G = 6.674e-11 m³/kgs²

    m₁ and m₂ are the masses of the two objects in kg

    r is the distance in meters between their centers

Still have questions? Get your answers by asking now.