Answer:
Explanation:
Let m be mass of each sphere and θ be angle, string makes with vertex in equilibrium.
Let T be tension in the hanging string
T cosθ = mg ( for balancing in vertical direction )
for balancing in horizontal direction
Tsinθ = F ( F is force of repulsion between two charges sphere)
Dividing the two equations
Tanθ = F / mg
tan17 = F / (7.1 x 10⁻³ x 9.8)
F = 21.27 x 10⁻³ N
if q be charge on each sphere , force of repulsion between the two
F = k q x q / r² ( r is distance between two sphere , r = 2 x .7 x sin17 = .41 m )
21.27 x 10⁻³ = (9 X 10⁹ x q²) / .41²
q² = .3973 x 10⁻¹²
q = .63 x 10⁻⁶ C
no of electrons required = q / charge on a single electron
= .63 x 10⁻⁶ / 1.6 x 10⁻¹⁹
= .39375 x 10¹³
3.9375 x 10¹² .
Answer:
D
Explanation:
Political scientists use political models to describe the political climate, which is an aggregate mood or opinion of a political society at a point in time.
Answer : The final pressure in the two containers is, 2.62 atm
Explanation :
Boyle's Law : It is defined as the pressure of the gas is inversely proportional to the volume of the gas at constant temperature and number of moles.
Thus, the expression for final pressure in the two containers will be:
where,
= pressure of N₂ gas = 4.45 atm
= pressure of Ar gas = 2.75 atm
= volume of N₂ gas = 3.00 L
= volume of Ar gas = 2.00 L
P = final pressure of gas = ?
V = final volume of gas = (4.45 + 2.75) L = 7.2 L
Now put all the given values in the above equation, we get:
Thus, the final pressure in the two containers is, 2.62 atm
Answer:
Explanation:
When unpolarized light passes through the first polarizer, the intensity of the light is reduced by a factor 1/2, so
(1)
where I_0 is the intensity of the initial unpolarized light, while I_1 is the intensity of the polarized light coming out from the first filter. Light that comes out from the first polarizer is also polarized, in the same direction as the axis of the first polarizer.
When the (now polarized) light hits the second polarizer, whose axis of polarization is rotated by an angle with respect to the first one, the intensity of the light coming out is
(2)
If we combine (1) and (2) together,
(3)
We want the final intensity to be 1/10 the initial intensity, so
So we can rewrite (3) as
From which we find
A heat pump is a device that puts out heat. It involves pumping a lever over and over to get energy so it can work.