Two uncharged, conducting spheres are separated by a distance d. When charge −Q is moved from sphere A to sphere B, the Coulomb force between them has magnitude F0.

(a)Is the Coulomb force attractive or repulsive?

attractive repulsive

(b) If an additional charge −Q is moved from A to B, what is the ratio of the new Coulomb force to the original Coulomb force,(c) If sphere B is neutralized so it has no net charge, what is the ratio of the new to the original Coulomb force,

Aboxcar traveling at 12 m/s approaches a string of 5 identical boxcars sitting stationary on the track. the moving boxcar collides and links with the stationary cars and they all move off together along the track. what is the final speed of the cars immediately after the collision? (you may take the mass of each boxcar to be 18,537 kg.)

Sawyer is studying diffraction. he draws a diagram of a plane wave to show how light waves travel. which best describes sawyer’s error? the wave fronts should be perpendicular to the direction in which the waves move. the arrow showing the direction of movement of the waves should be pointing to the left. the arrow showing the direction of movement of the waves should be pointing downward. the wave fronts should be both parallel and perpendicular to the direction in which the waves move.

Ihave a density of 1.61g/cm^3 and a mass of 28g. find the missing value