What electric field strength will cause the bead to hang suspended in the air?

[cemar.]

1. A 0.180g plastic bead is charged by the addition of 0.700 x 10^10 excess electrons. What electric field strength will cause the bead to hang suspended in the air?



2. Is amount of excess electrons the exact same as the charge of the bead??



3. I am sure you use F=qE. But I am pretty stuck at the rest of it. I am sure there is a formula or soemthing i missed in lecture considering my prof is a little loopy.

 

[nicksauce]

Set qE = mg. q is the charge of 0.7 * 10^10 electrons, m is the mass of the bead, g is acceleration due to gravity. Shouldn't be too hard.

 

[Moetasim]

1. To determine the electric field strength that will cause the bead to hang suspended in the air, we can use the equation F=qE, where F is the force acting on the bead, q is the charge of the bead, and E is the electric field strength. We can rearrange this equation to solve for E: E = F/q. In this case, the force acting on the bead is the weight of the bead, which is equal to its mass (0.180g) multiplied by the acceleration due to gravity (9.8 m/s^2). The charge of the bead is given as 0.700 x 10^10 excess electrons, which we can convert to the unit of Coulombs (C) using the charge of one electron (1.602 x 10^-19 C). Therefore, the charge of the bead is 1.1214 x 10^-9 C. Plugging these values into the equation, we get E = (0.180g x 9.8 m/s^2) / (1.1214 x 10^-9 C) = 1.57 x 10^10 N/C. Therefore, the electric field strength required to suspend the bead in the air is 1.57 x 10^10 N/C.


2. No, the amount of excess electrons is not necessarily the same as the charge of the bead. The charge of the bead is determined by the number of excess electrons and their individual charge. For example, if the bead had 0.700 x 10^10 excess electrons, but they were all neutralized by an equal number of protons, the bead would have no net charge.


3. It is correct that we use the equation F=qE to solve for the electric field strength. In order to use this equation, we need to know the force acting on the bead and the charge of the bead. As mentioned in the first question, the force acting on the bead is its weight, and the charge of the bead can be determined by converting the number of excess electrons to Coulombs. If you are still unsure, I would recommend reviewing your lecture notes or textbook to see if there are any additional formulas or information that may be helpful. It is also a good idea to ask your professor for clarification if you are still stuck.