Two balls, each with a mass of 0.845 kg, exert a gravitational force of 8.43 × 10−11 N on each other. How far apart are the balls? The value of the universal gravitational constant is 6.673 × 10−11 N m2/kg2. Answer in units of m.  

Expert Answers

An illustration of the letter 'A' in a speech bubbles

The Universal Gravitation Law states that the gravitational force between two objects is directly proportional to the product of their masses, and inversely proportional to the square of the distance between them.  The proportionality constant is the universal gravitational constant G. The equation for this law is:

`F = G (m_1 m_2)/d^2`

You need to solve for d, the distance between the two objects. Here's the data you've provided:

F = 8.43 x10^(-11) N

m1 = m2 = 0.85 kg

G = 6.673 x 10^(-11) N (m^2)/(kg^2

Now we'll substitute these values into the equation:

`d^2 = G(m_1 m_2)/F = 6.673 x 10^(-11)(N m^2/(kg)^2)(0.85kg)^2/(8.43x10^(-11)N`  

`d=sqrt(0.57m^2) = 0.75 m`


The distance between the objects is 0.75 meters. 


Approved by eNotes Editorial Team

We’ll help your grades soar

Start your 48-hour free trial and unlock all the summaries, Q&A, and analyses you need to get better grades now.

  • 30,000+ book summaries
  • 20% study tools discount
  • Ad-free content
  • PDF downloads
  • 300,000+ answers
  • 5-star customer support
Start your 48-Hour Free Trial