Aplastic rod 1.3 m long is rubbed all over with wool, and acquires a charge of -3e-08 coulombs. we choose the center of the rod to be the origin of our coordinate system, with the x-axis extending to the right, the y-axis extending up, and the z-axis out of the page. in order to calculate the electric field at location a = < 0.7, 0, 0 > m, we divide the rod into 8 pieces, and approximate each piece as a point charge located at the center of the piece. (a) what is the length of one of these pieces? â„“ = 0.1625 m (b) what is the location of the center of piece number 6? e m. (c) how much charge is on piece number 6? (remember that the charge is negative.) e coulombs (d) approximating piece 6 as a point charge, what is the electric field at location a due only to piece 6? 6 = e n/c (e) to get the net electric field at location a, we would need to calculate due each of the 8 pieces, and add up these contributions. if we did that, which arrow above would best represent the direction of the net electric field at location a?

(a) The plastic rod has a length of L=1.3m. If we divide by 8, we get the length of each piece:


(b) The center of the rod is located at x=0. This means we have 4 pieces of the rod on the negative side of x-axis, and 4 pieces on the positive side. So, starting from x=0 and going towards positive direction, we have: piece 5, piece 6, piece 7 and piece 8. Each piece is 0.1625 m long. Therefore, the center of piece 5 is at 0.1625m/2=0.0812 m. And the center of piece 6 will be shifted by 0.1625m with respect to this:


(c) The total charge is . To get the charge on each piece, we should divide this value by 8, the number of pieces:


(d) We have to calculate the electric field at x=0.7 generated by piece 6. The charge on piece 6 is the value calculated at point (c):

If we approximate piece 6 as a single  charge, the electric field is given by

where  and d is the distance between the charge (center of piece 6, located at 0.2437m) and point a (located at x=0.7m). Therefore we have

poiting towards the center of piece 6, since the charge is negative.

(e) missing details on this question.

Electoral current force mechanical advantage if the wheel and axle is 2 n and the output force is 20 n

Then the answer would be d then