Electric Force: While working in a University research laboratory your group is given the job of testing an electrostatic scale, which is used to precisely measure the weight of small objects. The device consists of two very light but strong strings attached to a support so that they hang straight down. An object is attached to the other end of each string. One of the objects has a very accurately known weight while the other object is the unknown. A power supply is slowly turned on to give each object an electric charge. This causes the objects to slowly move away from each other. When the power supply is kept at its operating value, the objects come to rest at the same horizontal level. At that time, each of the strings supporting them makes a different angle with the vertical and that angle is measured. To test your understanding of the device, you first calculate the weight of an unknown sphere from the measured angles and the weight of a known sphere. Your known is a standard sphere with a weight of 2.5 N supported by a string that makes an angle of 0.15 radians with the vertical. The unknown sphere's string makes an angle of 0.35 radians with the vertical. As a second step in your process of understanding this device, estimate the net charge on a sphere necessary for the observed deflection if a string were 10.1 cm long.