Correction
A student measures the mass <em><u>8cm3</u></em> block of brown sugar to be 12.9g. what is the density of the brown sugar
Answer:

Explanation:
Density is defined as mass per unit volume of an object expressed as
where
is the density, m is the mass of sugar and v is the volume of the sugar. Considering that the volume is given as 8cm3 for sugar then we substitute this for v and mass of 12.9 g we substitute for g then the density will be

Your answer would be A. Halogens
The electrostatic force between two charges q1 and q2 is given by

where

is the Coulomb's constant and r is the distance between the two charges.
If we use F=19.2 N and q1=q2=-3.0 C, we can find the value of r, the distance between the two charges by re-arranging the previous formula:
Answer:
Part a)

Part b)

Explanation:
Part a)
As we know that electric field intensity due to some given charge distribution is given as

now electric flux through a spherical surface of radius r is given as


now by Guass law we know that


now volume charge density is given as


Part b)
Total charge inside the radius R is given as

Answer
given,
D = 50 mm = 0.05 m
d = 10 mm = 0.01 m
Force to compress the spring




F = 3160 N
stress correction factor from stress correction curve is equal to 1.1
now, calculation of corrected stress


= 442.6 Mpa
The tensile strength of the steel material of ASTM A229 is equal to 1300 Mpa
now,



since corrected stress is less than the
hence, spring will return to its original shape.