What speed should a spaceship of mass 5.21 × 10⁷ kg moving around a planet only by the gravitational force be, if the distance between them is 6.27 × 10⁸ m and the mass of the planet is 4.76 × 10²⁶ kg? Estimate G at 6.67 × 10⁻¹¹ N (m/kg)²

a charge 3q is at the origin, and a charge −2q is on the positive x axis at x=a. part a where on the x-axis would you place a third charge so it would experience no net electric force? enter an expression for the exact answer, which will involve a square-root sign. (do not enter an approximate decimal answer.)

where are the vectors ?

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.