The refractive index for glycerine is
, while for air it is
.
When the light travels from a medium with greater refractive index to a medium with lower refractive index, there is a critical angle over which there is no refraction, but all the light is reflected. This critical angle is given by:
where n1 and n2 are the refractive indices of the two mediums. If we susbtitute the refractive index of glycerine and air in the formula, we find the critical angle for this case:
Lower resistivity means higher conductivity: among these materials, the best conductor is silver, therefore it must be the material with lowest resistivity among those. We can also have a look at the value of resistivity of the different materials listed in the problem, to check our answer. The resistivities of the materials are the following:
Wood:
Salt water:
Silver:
Lead:
<span>We see that the material with lowest resistivity among those is silver, therefore the correct answer is silver.</span>
Answer:
The right answer is D) the total momentum of the system is 0.047 kg · m/s toward the right.
Explanation:
Hi there!
The total momentum of the system is given by the sum of the momentum vectors of each cart. The momentum is calculated as follows:
p = m · v
Where:
p = momentum.
m = mass.
v = velocity.
Then, the momentum of the system will be the momentum of cart A plus the momentum of cart B (let´s consider the right as the positive direction):
mA · vA + mB · Vb
0.450 kg · 0.850 m/s + 0.300 kg · (- 1.12 m/s) = 0.047 kg · m/s
The right answer is D) the total momentum of the system is 0.047 kg · m/s toward the right.
I think the correct answer from the choices listed above is option D. The model of the universe that suggests that the sun is the center of the universe was first brought by Copernicus. His model is known as the "Sun centered model".
