Answer:
Explanation:
For the first case , the expression for electrostatic force can be given by the following .
F = K x 8Q x 2Q / r² where k is a constant .
F = K 16 Q² / r²
When they touch , some charge is neutralized . Net charge remaining
= 8Q - 2 Q = 6 Q
Charge on each sphere = 6Q/2 = 3 Q .
Force between them
F₁ = k 3Q x 3 Q / r² = k 9 Q² / r²
F₁ / F = 9 / 16
F₁ = 9 F / 16 .
Coulomb's Law: Force = k x q1x q2 divided distance square
where k=9x10^9 , q1 and q2 are the charge
So if you distance is halved, your force is stronger by 4 times
and if you distance is doubled, your force is 1/4
Ask me again if you aren't clear :)
Move the decimal point to:
Left : (if the exponent of ten is a negative number -) ... OUR CASE HERE (-2)
or to
Right : (if the exponent is positive +).
You should move the point as many times as the exponent indicates.
Do not write the power of ten anymore.
So, standard form is:
Two points to the left {Exponent of Ten is Negative (-2)}
0.059 ... (without the 10)
Answer:
a. 960 W b. One 1 kW room heater
Explanation:
a. The rate of heat conduction P = kA(T₂ - T₁)/d where k = 2 × 0.040 W/m-K = 0.080 W/m-K since the thermal conductivity of glass wool is 0.040 W/m-K and that of the material is twice the thermal conductivity of glass wool, A = area of walls = 120 m², T₁ = outside surface temperature = 5.0 °C, T₂ = inside surface temperature = 18.0 °C and d = thickness of wall = 13.0 cm = 0.13 m
P = kA(T₂ - T₁)/d
= 0.080 W/m-K × 120 m²(18.0 °C - 5.0 °C)/0.13 m
= 9.6 Wm/K × 13 K/0.13 m
= 124.8 Wm/0.13 m
= 960 W
b. The number of 1 kW room heater required will be
n = rate of heat conduction/power of one room heater = 960 W/ 1 kW = 960 W/1000 W = 0.96 ≅ 1
So we need only one 1 kW room heater.
Answer:
I hope this will help you
Explanation:
When two neutral objects come into contact--especially in a dry environment--electrons can be knocked loose from one object and picked up by the other. The object that gains electrons becomes negatively charged, while the object that loses electrons becomes positively charged. Objects with like charges repel each other, while those with opposite charges attract each other. This phenomenon--in which objects acquire an electric charge and exert a force on one another--is what we call static electricity.
