Q: What is the critical angle for total internal reflection for light traveling from glass ($$n = 1.50) to $$air ($$n = 1.00$$)?

$$\theta_c = \arcsin\left(\dfrac{1.00}{1.50}\right)$$

Q: Which equation correctly expresses Snell's Law for refraction?

$$n_a \sin \theta_a = n_b \sin \theta_b$$

Question 1

Which of the following best describes the right-hand rule for determining the direction of angular velocity or angular momentum vectors?

Accepted Answer

Curl the fingers of your right hand in the direction of rotation; your thumb points in the direction of the angular vector.

Question 2

A force of $$10\ \mathrm{N} is $$applied tangentially to a wheel of radius $$0.5\ \mathrm{m}. $$What is the magnitude of the torque produced?

Accepted Answer

$$5.0\ \mathrm{N \cdot m}$$

Question 3

According to Newton's 2nd Law for rotation, which equation correctly relates torque ($$	au$$), moment of inertia ($$I$$), and angular acceleration ($$\alpha$$)?

Accepted Answer

$$	au = I \alpha$$

Question 4

A disk rotates with an angular velocity $$\omega$$ and has a moment of inertia $$I. $$What is its angular momentum $$L$$?

Accepted Answer

$$L = I \omega$$

Question 5

Which of the following is true about the conservation of angular momentum?

Accepted Answer

Angular momentum is only conserved if there is no net external torque.

Question 6

A person spins on a frictionless stool with arms extended. When they pull their arms in, what happens to their angular velocity and why?

Accepted Answer

Angular velocity increases because moment of inertia decreases, conserving angular momentum.

Question 7

Which equation gives the index of refraction $$n$$ for a material?

Accepted Answer

$$n = \dfrac{c}{v}$$

Question 8

A light ray passes from water ($$n = 1.33) $$into air ($$n = 1.00) at an $$angle of incidence of $$60^\circ. $$What is the angle of refraction in air? (Use Snell's Law.)

Accepted Answer

$$\$$theta_2$$ = \arcsin\left(\dfrac{1.00}{1.33} \sin 60^\circ\right)$$

Question 9

Which of the following best describes total internal reflection?

Accepted Answer

It occurs when the angle of incidence exceeds the critical angle and all light is reflected back into the denser medium.

Question 10

What is the critical angle for total internal reflection for light traveling from glass ($$n = 1.50) to $$air ($$n = 1.00$$)?

Accepted Answer

$$	heta_c = \arcsin\left(\dfrac{1.00}{1.50}ight)$$

Question 11

Which region of the electromagnetic spectrum has the highest energy and shortest wavelength?

Accepted Answer

Gamma rays

Question 12

Why do insects see flowers differently than humans?

Accepted Answer

Insects can see ultraviolet light, which reveals patterns not visible to humans.

Question 13

Which of the following statements about the ray approximation in optics is correct?

Accepted Answer

It is valid for both spherical and planar waves.

Question 14

A light ray enters a material with a higher index of refraction. What happens to the speed and direction of the light?

Accepted Answer

The speed decreases and the ray bends toward the normal.

Question 15

Which equation correctly expresses Snell's Law for refraction?

Accepted Answer

$$n_a \sin 	heta_a = n_b \sin 	heta_b$$

Question 16

A rough surface produces which type of reflection?

Accepted Answer

Diffuse reflection

Question 17

Which of the following best describes the relationship between wavelength, frequency, and energy in the electromagnetic spectrum?

Accepted Answer

Shorter wavelength means higher frequency and higher energy.

Question 18

A ray of light passes from air ($$n = 1.00) $$into diamond ($$n = 2.42) at an $$angle of $$30^\circ to $$the normal. What is the angle of refraction inside the diamond?

Accepted Answer

$$\$$theta_2$$ = \arcsin\left(\dfrac{1.00}{2.42} \sin 30^\circ\right)$$

Question 19

Which of the following is a real-world application of total internal reflection?

Accepted Answer

The operation of optical fibers in telecommunications.

Rotational Motion and Geometric Optics: Key Concepts and Applications

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