Charges of +3 µC and –5 µC are 2 mm from each other. The –5 µC charge is replaced with a +5 µC charge. How will the electrical force between the charges compare with the original force?
same force, but in the opposite direction
same force, but in the same direction
greater force, but in the opposite direction
greater force, but in the same direction

On a frictionless air track, a blue glider with mass 0.200 kg is moving to the right with a speed of 8.00 m/s. it strikes a red glider that has mass 0.600 kg and that is initially at rest. after the collision, the blue glider is moving to the left with a speed of 3.00 m/s.(a) what are the magnitude and direction of the velocity of the red glider after the collision? (b) is this collision elastic?