| 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.
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
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