Density, density, density. (a) a charge -312e is uniformly distributed along a circular arc of radius 5.70 cm, which subtends an angle of 71o. what is the linear charge density along the arc? (b) a charge -312e is uniformly distributed over one face of a circular disk of radius 3.70 cm. what is the surface charge density over that face? (c) a charge -312e is uniformly distributed over the surface of a sphere of radius 4.20 cm. what is the surface charge density over that surface? (d) a charge -312e is uniformly spread through the volume of a sphere of radius 4.00 cm. what is the volume charge density in that sphere?

(a): Linear charge density of the circular arc =

(b): Surface charge density of the circular arc =

(c): Volume charge density of the sphere =  

Explanation:

Given:

We know, e is the elementary charge whose value is

Therefore,

Also, the length l of a circular arc is given as:

The linear charge density of the arc is defined as the charge per unit length of the arc.

Given:

Surface area of the circular disc,

The surface charge density of the disc is defined as the charge per unit area of the disc.

Given:

Volume of the sphere,

The volume charge density of the sphere is defined as the charge per unit volume of the sphere.

can be answered using momentum.

momentum = p

p1= mass1 * velocity1

p1 = p2

therefore

p1 = 6kg * 4m/s

p1 = 24kgm/s

p2=m2 * v2

24 kgm/s = 7kg * v2

v2 = 24 kgm/s / 7kg

v2= 3.42 m/s

false br