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2 years ago

Which of the following statements correctly describes the index of refraction of a material? Select all that apply.

Physics

1 answer:

mote1985 [20]2 years ago

4 0

Answer:

Option C and D only

Explanation:

Option A is incorrect because refractive index of a material is the ratio of speed of light in vacuum to the speed of light in a any given medium

Option B is correct as the speed of light in vacuum is always greater than the speed of light in any given medium.

Option C is correct

Option D is incorrect

Option E is incorrect because the denser the medium the more is the refractive index. Water is denser than air, hence it should have more refractive index as compared to that of air.

You might be interested in

Which of the following air conditions would be least likely to have precipitation 10 pts

Harrizon [31]

Answer:

D. Cold, dry air

(Just took the quiz and got it right, hope this helps :3)

5 0

3 years ago

A block moves along a table at a constant velocity and then rolls off the edge of the table. The forces that should be included

Alla [95]

Answer:

Gravity

Explanation:

When the ball is falling to the ground, there is only one force- gravity. In some cases, there may be air resistance, but that seems to be neglected here.

Normal force:

Cannot be included. Normal force is only applicable when object is on a surface, and it acts perpendicular to the surface. Since the ball is falling, there is no surface, and therefore no normal force. This question gives you unnecessary information, designed to trick you. Please remember when normal force is applicable.

Friction force:

Also only applicable when object is moving, and is on the table. Friction only applies when there is an applied force. There is no applied force when the ball is falling, so therefore no friction force.

Force of fall:

First of all, what is this? There is nothing called force of fall.

Gravity:

This is the only one that applies. Just draw a vector arrow from the bottom of the ball and label it mg (acceleration due to gravity).

3 0

2 years ago

Determine the length of the tungsten filament in a 100 watt lightbulb given: (i) the resistivity of tungsten is 5.6 × 10−8 Ω · m

svetoff [14.1K]

Answer:

0.34148 m

Explanation:

$\rho$ = Resistivity of tungsten = $5.6\times 10^{-8}\ \Omega m$

d = Diameter = 0.0018 inch

r = Radius = $\dfrac{r}{2}=\dfrac{0.0018}{2}=0.0009\ in$

$r=0.0009\times 0.0254=0.00002286\ m$

$\alpha$ = Temperature coefficient of tungsten = $0.0045 /^{\circ}C$

Power is given by

$P=\dfrac{V^2}{R}\\\Rightarrow R=\dfrac{V^2}{P}\\\Rightarrow R=\dfrac{120^2}{100}\\\Rightarrow R=144\ \Omega$

We have the equation

$R_2=R_1[1+\alpha(T_2-T_1)]\\\Rightarrow R_1=\dfrac{R_2}{1+\alpha(T_2-T_1)}\\\Rightarrow R_1=\dfrac{144}{1+0.0045(2550-25)}\\\Rightarrow R_1=11.64812\ \Omega$

Resistance is given by

$R=\rho\dfrac{l}{A}\\\Rightarrow l=\dfrac{RA}{\rho}\\\Rightarrow l=\dfrac{11.64812\times \pi (0.00002286)^2}{5.6\times 10^{-8}}\\\Rightarrow l=0.34148\ m$

The length of the filament is 0.34148 m

7 0

2 years ago

force of 10 lb is required to hold a spring stretched 4 in. beyond its natural length. How much work W is done in stretching it

Yanka [14]

Answer:

Given force=10lb

L1=4in converting to feet

But 0.08333ft= 1 inch

Then 4 inch is 0.3332

6inch is 0.49998

But hookes law states

F=Kx where F is force,K is the force constant ,X

K=F/X=10/0.3333=30N/m

Integrating this

Integral of 30x with limit 0.333 to 0.5

F=30x^2/2=15x^2substing the limit

F=(15(0.5^2-0.33^2)=2.08ft-lb

Explanation:

3 0

2 years ago

A stationary boat bobs up and down with a period of 2.4 s when it encounters the waves from a moving boat.

lapo4ka [179]

It seems like the question is asking for the frequency.
Given:
Time period (T) = 2.4 sec

Frequency (f) =?

We know that the formula for frequency is:

Frequency (f) = 1/time period (T)

= 1 / 2.4 s

= 0.42 Hz. is the frequency for this problem.

8 0

2 years ago