A person holding a lunch bag is moving upward in a hot air balloon at a constant speed of 7.7 m/s . When the balloon is 21 m above the ground, she accidentally releases the bag. Part A What is the speed of the bag just before it reaches the ground

Point charges q1=+2.00μc and q2=−2.00μc are placed at adjacent corners of a square for which the length of each side is 1.50 cm . point a is at the center of the square, and point b is at the empty corner closest to q2. take the electric potential to be zero at a distance far from both charges. part a what is the electric potential at point a due to q1 and q2? express your answer with the appropriate units.