Answer:
a. Big Bang Theory explains the beginning of the universe. The entire matter of the universe is believed to be concentrated in a single point. This point had infinite density. At time, t = 0, at the big bang, universe started expanding and cooling down. This theory is most widely accepted theory describing the beginning of the universe. It is not considered as hypothesis because of the evidences received by the scientists- detection of cosmic microwave background, red shift of the light received from the galaxies indicating that universe is expanding.
b. Cosmic Microwave background radiation is a faint radiation having average temperature of 3 K detected every where around from the sky. This is a residual radiation from 400,000 years after the beginning of the universe. The universe was very hot and dense at the beginning and thus, opaque. Hence, detection of the CMB has provided the evidence of Big bang theory.
c. Scientists have proposed three models of the universe:
1. closed universe- The universe has finite volume and curves around itself. The space-time has positive curvature.
2. open universe - The universe has infinite volume and has a negative curvature.
3. flat universe - The universe has zero curvature. It has infinite volume. The actual density of the universe is equal to the critical density of the universe. The expansion rate slows down over time. This is the most widely accepted model.
Answer:
Wc = 7.84 weight of crown
Ww = 7.84 - 6.86 = .98 weight of water displaced
Density = 7.84 / .98 = 8 crown is 8 X that of water
Since gold has a density of 19.3 that of water the crown is certainly not 100 percent (if any) gold
Answer:
dx/Dt x B . x =0
Explanation:
Let's calculate the work and the magnetic force, the expression for magnetic force is
F = qv x B
Bold indicate vector quantities, the expression for the job is
W = F. X
Let's replace in this equation
W = q v x B . X
The definition of speed is
v = dX / dt
With what work is left
W = q dX / dt x B . X
As we can see the vector product gives us a vector perpendicular to dX and its scalar product by X of zero
Second part
The speed a vector and although the magnitude is constant the change of direction implies a change in the speed.
Let's calculate the magnitudes of speed (speed)
F = qv B sin θ
F = ma
q v B sin θ = ma
a = qvB / m senT
This acceleration is perpendicular to the magnetic field and the velocity, so it does not change if magnitude but its direction, it is directed to the center of the circle.
| v | = q vB/m sin θ
Explanation:
The given data is as follows.
q = 6.0 nC = 
inner radius (r) = 1.0 cm = 0.01 m (as 1 cm = 100 m)
So, there will be same charge on the inner surface as the charge enclosed with an opposite sign.
Formula to calculate the charge density is as follows.
.......... (1)
Since, area of the sphere is as follows.
A = 
........... (2)
Hence, substituting equation (2) in equation (1) as follows.
= 
= 
or, = 4.77 
Thus, we can conclude that the resulting charge density on the inner surface of the conducting sphere is 4.77 .
Yes, it is true to a certain that the number of outer shell electrons determines the chemical properties of an element, only because this determines how the element interacts with other elements.
