# Problems : Electric Charge and Electric Force

- Two positive point charges,
*Q*_{1}= 1 μCand*Q*1 μC , are separated by a distance d. Which is larger in magnitude, the force that Q_{2}=_{1}exerts on*Q*_{2}or the force that*Q*exerts on_{2 }*Q*_{1}? - What is the magnitude of the force a +25 μC
- How many electrons make up a charge of —38.0 μC ?
- Particles of charge +75
*μC*, +40*μC*, and —85*μC* - Sophy scuffing her feet on a wool rug on a dry day accumulates a net charge of —46 μC. How many excess electrons does she get, and by how much does her mass increase?
- A charge
*Q*is transferred from an initially uncharged plastic ball to an identical ball 10 cm away. The force of attraction is then 18 mN. How many electrons were transferred from one ball to the other? - Three charged particles are placed at the corners of an equilateral triangle of side 1.20 m. The charges are +7.0
*μC*—8.0*μC*, —6.0*μC*.