Exercise 2.3 B

Difficulty Secondary School High school/other
Basic Easy
★★ Demanding Basic
★★★ Demanding
★★★★ Difficult
★★★★★ Very difficult

Specify the index of refraction of glass with the critical angle of the total internal reflection.

Answer: 1,48

Exercise 2.3 C

Difficulty Secondary School High school/other
Basic Easy
★★ Demanding Basic
★★★ Demanding
★★★★ Difficult
★★★★★ Very difficult

Specify the index of refraction of glass.

Answer: 1,5

Exercise 2.3 D

Difficulty Secondary School High school/other
Basic Easy
★★ Demanding Basic
★★★ Demanding
★★★★ Difficult
★★★★★ Very difficult

Define the index of refraction of glass.

Answer: 1,5

Exercise 2.4 A

Difficulty Secondary School High school/other
Basic Easy
★★ Demanding Basic
★★★ Demanding
★★★★ Difficult
★★★★★ Very difficult

In the video, the light of the laser hits the diffraction grating. How many slits per millimeter can the diffraction grating contain.

Answer: 480 – 520 pieces ($500\pm20$ gap/mm)

Exercise 2.5 A

Difficulty Secondary School High school/other
Basic Easy
★★ Demanding Basic
★★★ Demanding
★★★★ Difficult
★★★★★ Very difficult

Determine the length of the spring when there isn’t any mass suspended from it.

Answer: 20 cm

Exercise 2.5 B

Difficulty Secondary School High school/other
Basic Easy
★★ Demanding Basic
★★★ Demanding
★★★★ Difficult
★★★★★ Very difficult

Define the mass of an unknown object.

Answer: 280 g

Exercise 2.5 C

Difficulty Secondary School High school/other
Basic Easy
★★ Demanding Basic
★★★ Demanding
★★★★ Difficult
★★★★★ Very difficult

Determine the value of acceleration due to gravity g with different lengths of a pendulum.

Tip 1: The oscillation time of a simple gravity pendulum is $T=2\pi\sqrt{\frac{l}{g}}$
Tip 2: Move the information to $(T^2,l)$ –coordinate system.
Answer: $9{,}9\ \frac{m}{s^2}$

Exercise 2.5 D

Difficulty Secondary School High school/other
Basic Easy
★★ Demanding Basic
★★★ Demanding
★★★★ Difficult
★★★★★ Very difficult

Determine the position of the spring’s head as a function of time.

Tip: The waveform equation is a form $y=Asin(2\pi ft)$
Answer: $y=0,315\ m+0,05\ m\cdot\sin{\left(\frac{2\pi}{0,712\ s}\cdot\left(t-60{,}462\ s\right)\right)}$, where $t\geq60{,}462\ s$

Exercise 2.6 A

Difficulty Secondary School High school/other
Basic Easy
★★ Demanding Basic
★★★ Demanding
★★★★ Difficult
★★★★★ Very difficult

Determine the speed of the sound. (Note: Video contains audio).

Answer: $320\ \frac{m}{s}$

Exercise 2.7 A

Difficulty Secondary School High school/other
Basic Easy
★★ Demanding Basic
★★★ Demanding
★★★★ Difficult
★★★★★ Very difficult

Determine the damping ratio (constant that describes the strength of the damping force), damping factor, natural frequency, angular frequency of the harmonic oscillator, and the frequency and angular frequency of the damped oscillator.

Answer: Harmonic oscillator
Damping ratio C=1,01
Damping factor δ=0,012592215 rad/s
Natural frequency $f_{0}$=1,146187397Hz
Natural angular frequency $ω_{0}$=7,20170781 rad/s

Damped oscillator
Frequency $f_{1}$=1,146185644Hz
Angular frequency $ω_{1}$=7,201696801 rad/s