If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content

Understand: Newton’s law of universal gravitation

You might need: Calculator


The gravitational force between a pair of identical twins who each have a mass of 75, point, 6, start text, space, k, g, end text is 6, point, 126, times, 10, start superscript, minus, 10, end superscript, start text, N, end text.
Calculate the distance between the twins.
Write your answer using three significant figures.
  • Your answer should be
  • an integer, like 6
  • a simplified proper fraction, like 3, slash, 5
  • a simplified improper fraction, like 7, slash, 4
  • a mixed number, like 1, space, 3, slash, 4
  • an exact decimal, like 0, point, 75
  • a multiple of pi, like 12, space, start text, p, i, end text or 2, slash, 3, space, start text, p, i, end text
start text, m, end text