Answer:
Explanation:
Let the critical angle be C .
sinC = 1 / μ where μ is index of refraction .
sinC = 1 /1.2
= .833
C = 56°
Then angle of refraction r = 90 - 56 = 34 ( see the image in attached file )
sin i / sinr = 1.2 , i is angle of incidence
sini = 1.2 x sinr = 1.2 x sin 34 = .67
i = 42°.
The correct answer is C. 1995
Explanation:
The graph shows the changes in the harvest of Atlantic cod. In general, this graph illustrates how the peak occurred in the 1980s but then there was a sudden and sharp decline in 1995. Indeed, 1995 is the year with the lowest number of harvested cod as in this year there were approximately least than 10 thousand metric tonnes of cods. Also, this year shows the collapse of fishing stocks or that the population of this fish collapsed, which made it impossible to harvest as many fish as in previous years. According to this, the year that shows the collapse of fishing stocks is 1995.
Answer:
The current in the rods is 171.26 A.
Explanation:
Given that,
Length of rod = 0.85 m
Mass of rod = 0.073 kg
Distance 
The rods carry the same current in the same direction.
We need to calculate the current
I is the current through each of the wires then the force per unit length on each of them is
Using formula of force


Where, m = mass of rod
l = length of rod
Put the value into the formula




Hence, The current in the rods is 171.26 A.
First, we calculate the mass of Phosphorous present:
283.88 x 0.4364
= 123.88 amu
Atomic mass of P is 31 amu
moles of P = mass / Ar
= 123.88 / 31
= 4.0 moles
We know that one mole of substance has 6.02 x 10²³ particles
Atoms of P = 4 x 6.02 x 10²³
= 2.41 x 10²⁴ atoms