Question

Three solid plastic cylinders all have radius 2.55 cm and length 5.46 cm. Find the charge of each cylinder given the following additional information about each one.

Cylinder (a) carries charge with uniform density 14.9 nC/m2 everywhere on its surface. 1.91*10e-10 Incorrect: Your answer is incorrect. Your response is off by a multiple of ten. C

Cylinder (b) carries charge with uniform density 14.9 nC/m2 on its curved lateral surface only. 1.30*10e-10 Incorrect: Your answer is incorrect. Your response is off by a multiple of ten. C

Cylinder (c) carries charge with uniform density 545 nC/m3 throughout the plastic. 6.08*10e-11 Incorrect: Your answer is incorrect. Your response is off by a multiple of ten. C

Answer 1

a)

Given :-

r = 2.55 x 10^-2 m

h = 5.46 x 10^-2 m

density = 14.9 nC/m^2

Total area = 2pi*r*h + 2pi*r^2 = 2pi*r(r + h)

Total charge = charge density x total area

Total charge = 14.9 x 10^-9 c/m^2 x 2pi*2.55*10^-2(2.55 x 10^-2 + 5.46 x 10^-2)

Total charge = 0.1911 x 10^-9 C = 0.1911 nC

b)

total charge = charge density x 2pi*r*h

total charge = 14.9 x 10^-9 C/m^2 x 2pi x 2.55 x 10^-2 x 5.46 x 10^-2

total charge = 0.13 nC

c)

total charge = charge density x pi*r^2*h

total charge = 545 x 10^-9 C/m^2 x pi x (2.55 x 10^-2)^2 x 5.46 x 10^-2

total charge = 0.060 nC