The mass m of the object = 5.25 kg
<h3>Further explanation</h3>
Given
k = spring constant = 3.5 N/cm
Δx= 30 cm - 15 cm = 15 cm
Required
the mass m
Solution
F=m.g
Hooke's Law
F = k.Δx

ELECTROSTATIC:
relating to stationary electric charges or fields as opposed to electric currents.
NEUTRAL:
nor negative nor positive/having no charge
POSITIVELY CHARGED:
positive charge occurs when the number of protons exceeds the number of electrons
NEGATIVELY CHARGED:
negative charge occurs when the number of electrons exceeds the number of protons.
COULOMB:
SI unit for electric charge. One coulomb is equal to the amount of charge from a current of one ampere flowing for one second.
MICROCOULOMB:
a unit of electrical charge equal to one millionth of a coulomb.
NANOCOULOMB:
Nanocoulombs are a unit of charge 1,000,000,000 times smaller than Coulomb.
CONSERVATION OF CHARGE:
constancy of the total electric charge in the universe or in any specific chemical or nuclear reaction
QUANTISATION OF CHARGE:
Charge quantization is the principle that the charge of any object is an integer multiple of the elementary charge.
Answer:
Because china was in war, and her parents didn't have enough money for to go to school.
Answer:
The bulb is not powered because the negative end of the battery is not connected to the electric current,making it dysfunctional. The electrons have to flow through the positive and negative ends of the battery in order for it to work.
Hope this helps.