Tippes 23

19- One object contains an excess of 5 x 1014 electrons and another has a deficiency of 4 x 1014 electrons. What is the force each exerts on the otherif the objects are 30 mm apart? Is it attraction or repulsion? ( 1e = 1.6 x 10-19 C, excess = -, deficiency = +. )
20- If it were possible to put 1C of charge on each of two spheres separated by a distance of 1 m, what would be the repulsive force in newtons.
21- How many electrons must be placedon each of two spheres separated by 4 mm in order to produce a repulsive force of one 400 N?
22- A –40-nC charge is placed 40 mm to the left of a +6-nCcharge. What is the resultant force on a –12-nC charge place 8 mm to the right of the +6-nC charge?
23- A 5-C charge is placed 6 cm to the right of a2-C charge. What is the resultant force on a –9 nC charge placed 2 cm to the left of the 2-C charge?
24- An equal number of electrons is placed ontwo metal spheres 3.0 cm apart in air. How many electrons are on each sphere if the resultant force is 4500 N?
25- A 4-nC charge is placed on a 4-gsphere that is free to move. A fixed 10-C point charge is 4 cm away. What is the initial acceleration of the 4-C charge?
26- What is theresultant force on a +2 C charge an equal distance of 60 mm from each of two –4-C charges that are 80 mm apart in air?
27- Two charges of +25 and +16 C are 80mm apart. A third charge of +60 C is placed between the other charges 30 mm from the +25 C charge. Find the resultant force on the third charge?