Acapacitor is made from two hollow, coaxial, iron cylinders, one inside the other. the inner cylinder is negatively charged and the outer is positively charged; the magnitude of the charge on each is 12.0 pc. the inner cylinder has a radius of 0.250 mm, the outer one has a radius of 5.00 mm, and the length of each cylinder is 22.0 cm.1.what is the capacitance? use 8.854×10−12 f/m for the permittivity of free space.2.what applied potential difference is necessary to produce these charges on the cylinders?

1) 17.65 * 10^-12 C/V; 2) 0.68 V

Explanation: In order to calculate the capacitance of one cylinder capacitor we have to use the following expression:

where and b are the inner and outer radius of teh cylinder, respectively. L is length of the cylinder.

Finally we also kwn that C=Q/ΔV

then we have

ΔV =Q/C

ΔV = 12 * 10^-12/17.65*10^-12= 0.68V

the average speed is 24.57 km/hr

work: w = fd (given)

work done by chet   =50*1 = 50 j

work done by mika =40*2 = 80 j

work done by sara =30*1.5 = 45 j

work done by bill =60*0.5 = 30 j

students in order from the greatest amount of work done to the least is mika> chet> sara> bill

hence option (b) is correct.