Physics

A carefully designed experiment can measure the gravitational force between masses of 9 kg. Given that the density of iron is 7860 kg/m3, what is the gravitational force between two 9.00-kg iron spheres that are touching in N?

asked by Tim
  1. V=4πR³/3
    Density ρ=m/V = 3•m/4•π•R³ = >
    R=cuberoot(3•m/4•π• ρ) = cuberoot(3•9•9/4•π•7860) =0.065 m.

    the gravitational constant
    G =6.67•10^-11 N•m²/kg²,

    F =G•m1•m2/R² = =6.67•10^-11•9²/0.065²=1.28•10^-6 N

    posted by Elena
  2. The third line

    R=cuberoot(3•m/4•π• ρ) = cuberoot(3•9/4•π•7860) =0.065 m.

    posted by Elena
  3. I'm supposed to get 3.21e-07 N.

    posted by Tim
  4. F =G•m1•m2/(2R)² = 6.67•10^-11•9²/(2•0.065)²=1.28•10^-6/4 =0.32•10^-6 N

    posted by Elena

Respond to this Question

First Name

Your Response

Similar Questions

  1. WSU PHY

    A carefully designed experiment can measure the gravitational force between masses of 8 kg. Given that the density of iron is 7860 kg/m3, what is the gravitational force between two 8.00-kg iron spheres that are touching?
  2. Physics

    A carefully designed experiment can measure the gravitational force between masses of 6 kg. Given that the density of iron is 7860 kg/m3, what is the gravitational force between two 6.00-kg iron spheres that are touching? The
  3. physics

    A carefully designed experiment can measure the gravitational force between masses of 9 kg. Given that the density of iron is 7860 kg/m3, what is the gravitational force between two 9.00-kg iron spheres that are touching? I can
  4. physics - science

    - two identical lead spheres have a combined mass of 12kg. the density of lead is 11400 kg m-3. find the radius of each sphere. calculate the gravitational force of attraction between the 2 spheres when they are touching. -two
  5. Physics Help

    A dumbbell has a mass m on either end of a rod of length 2a. The center of the dumbbell is a distance r from the center of the Earth, and the dumbbell is aligned radially. If r≫a, the difference in the gravitational force
  6. physics

    A dumbbell has a mass m on either end of a rod of length 2a. The center of the dumbbell is a distance r from the center of the Earth, and the dumbbell is aligned radially. If r≫a, the difference in the gravitational force
  7. Physics

    Two iron spheres each have a volume of 10 cm^3 and a mass of 78g. How many electrons must be placed on each sphere so that the electrostatic force of repulsion between them just balances the force of gravitational attraction?
  8. Physics HELP!!

    Two iron spheres each have a volume of 10 cm^3 and a mass of 78g. How many electrons must be placed on each sphere so that the electrostatic force of repulsion between them just balances the force of gravitational attraction?
  9. physics

    In introductory physics laboratories, a typical Cavendish balance for measuring the gravitational constant G uses lead spheres of masses 1.79 kg and 16.9 g whose centers are separated by 5.49 cm. Calculate the gravitational force
  10. Physics

    In introductory physics laboratories, a typical Cavendish balance for measuring the gravitational constant G uses lead spheres of masses 1.27 kg and 18.4 g whose centers are separated by 5.05 cm. Calculate the gravitational force

More Similar Questions