Hassan Mustafa Abdinur

𝐖𝐀𝐕𝐄-𝐋𝐄𝐍𝐆𝐓𝐇, 𝐕𝐄𝐋𝐎𝐂𝐈𝐓𝐘 & 𝐅𝐑𝐄𝐐𝐔𝐄𝐍𝐂𝐘 𝐎𝐅 𝐀 𝐖𝐀𝐕𝐄

𝐈𝐧𝐭𝐫𝐨𝐝𝐮𝐜𝐭𝐢𝐨𝐧

Waves are a fundamental concept in physics, and they can be described by their wavelength, velocity, and frequency. Understanding these properties is crucial for understanding various phenomena in physics, engineering, and other fields.

Definitions
- Wavelength (λ):
The distance between two consecutive points on a wave that are in phase with each other. It is typically measured in meters (m).

- Velocity (v):
The speed at which a wave propagates through a medium. It is typically measured in meters per second (m/s).

- Frequency (f):
The number of oscillations or cycles of a wave per second. It is typically measured in hertz (Hz).

RELATIONSHIP BETWEEN WAVELENGTH, VELOCITY, AND FREQUENCY
The relationship between wavelength, velocity, and frequency is given by the wave equation:

v = λf

This equation shows that the velocity of a wave is equal to the product of its wavelength and frequency.

Derivation of the Wave Equation
The wave equation can be derived by considering a wave propagating through a medium. Let's consider a wave with a wavelength λ and a frequency f. The time period of the wave is T = 1/f.

In a time T, the wave travels a distance λ. Therefore, the velocity of the wave is:

v = distance / time
= λ / T
= λf

Solved Examples
Example 1: Water Wave
A water wave has a wavelength of 10 meters and a frequency of 0.5 Hz. Calculate its velocity.

v = λf
= 10 m x 0.5 Hz
= 5 m/s

Example 2: Sound Wave
A sound wave has a frequency of 440 Hz and a velocity of 343 m/s in air. Calculate its wavelength.

λ = v / f
= 343 m/s / 440 Hz
= 0.78 m

Example 3: Light Wave
A light wave has a wavelength of 500 nm and a velocity of 3 x 10^8 m/s in vacuum. Calculate its frequency.

f = v / λ
= (3 x 10^8 m/s) / (500 x 10^-9 m)
= 6 x 10^14 Hz

NOTE
- The velocity of a wave depends on the medium it is propagating through.
- The frequency of a wave is a property of the source and does not change as the wave propagates through different media.
- The wavelength of a wave changes as it propagates through different media, but the frequency remains the same.

TYPES OF WAVES
There are several types of waves, including:

- Mechanical waves: These waves require a physical medium to propagate, such as water waves and sound waves.
- Electromagnetic waves: These waves do not require a physical medium to propagate, such as light waves and radio waves.
- Matter waves: These waves are associated with particles, such as electrons and atoms.

Applications of Waves
Waves have numerous applications in various fields, including:

- Communication: Waves are used to transmit information, such as radio waves and light waves.
- Medicine: Waves are used in medical imaging, such as ultrasound and MRI.

- Energy: Waves are used to generate energy, such as solar energy and wind energy.

Shariif Hassan Mustafa Abdinur

Date: 01 / 11 / 2025
Topic: Equilibrium of Forces
𝗥𝗲𝗳𝗲𝗿𝗲𝗻𝗰𝗲: 𝗣𝗵𝘆𝘀𝗶𝗰𝘀 𝗢𝗻𝗹𝗶𝗻𝗲 𝗖𝗹𝗮𝘀𝘀

Definition
Equilibrium occurs when the net force acting on an object is zero, resulting in no acceleration.

Types of Equilibrium
1. Static Equilibrium: Object is at rest.
2. Dynamic Equilibrium: Object is moving with constant velocity.

Conditions for Equilibrium
1. First Condition: The vector sum of all forces acting on an object must be zero.
ΣF = 0

2. Second Condition: The sum of all torques acting on an object must be zero.
Στ = 0

Key Concepts
1. Resultant Force: The vector sum of all forces acting on an object.
2. Equilibrant Force: A force that balances the resultant force.

Applications
1. Structural Analysis: Equilibrium is crucial for designing stable structures.
2. Mechanical Systems: Equilibrium is essential for understanding the behavior of mechanical systems.
3. Physics Problems: Equilibrium is a fundamental concept in solving physics problems involving forces.


Hassan Mustafa Abdinur

Date: 12 / 10 / 2025
Subject:𝑷𝒉𝒚𝒔𝒊𝒄𝒔
Topic: 𝐍𝐮𝐜𝐥𝐞𝐚𝐫 𝐏𝐚𝐫𝐭𝐢𝐜𝐥𝐞𝐬

Nuclear Particle
1⃣ Definition: Subatomic particles that make up the nucleus of an atom

Types:
1. Protons: Positively charged particles
2. Neutrons: Particles with no charge (neutral)
3. Nucleons: Collective term for protons and neutrons

2⃣ Properties of Nuclear Particles
- Protons:
- Charge: +1 elementary charge
- Mass: Approximately 1 atomic mass unit (amu)
- Neutrons:
- Charge: 0 (no charge)
- Mass: Approximately 1 amu

3⃣ Key Concepts
1. Atomic Number: The number of protons in an atom's nucleus (defines the element)
2. Mass Number: The total number of nucleons (protons + neutrons) in an atom's nucleus
3. Isotopes: Atoms of the same element with different numbers of neutrons

4⃣ Nuclear Forces
1. Strong Nuclear Force: The force that holds protons and neutrons together in the nucleus
2. Weak Nuclear Force: Involved in certain types of radioactive decay

5⃣ Applications
1. Nuclear Power: Energy generation through nuclear reactions
2. Medical Applications: Radioisotopes used in diagnosis and treatment of diseases
3. Scientific Research: Nuclear physics research helps us understand the universe and develop new technologies

Hassan Mustafa Abdinur

𝐏𝐡𝐲𝐬𝐢𝐜𝐬 𝐟𝐨𝐫𝐦 𝐨𝐧𝐞
𝐂𝐡𝐚𝐩𝐭𝐞𝐫: 𝐌𝐞𝐚𝐬𝐮𝐫𝐞𝐦𝐞𝐧𝐭𝐬
Topic: Fundamental and Derived Quantities

𝐅𝐮𝐧𝐝𝐚𝐦𝐞𝐧𝐭𝐚𝐥 𝐐𝐮𝐚𝐧𝐭𝐢𝐭𝐢𝐞𝐬
Fundamental quantities are basic physical quantities that cannot be defined in terms of other quantities. They are the foundation of the International System of Units (SI).

𝐄𝐱𝐚𝐦𝐩𝐥𝐞𝐬 𝐨𝐟 𝐅𝐮𝐧𝐝𝐚𝐦𝐞𝐧𝐭𝐚𝐥 𝐐𝐮𝐚𝐧𝐭𝐢𝐭𝐢𝐞𝐬
1. Length (meter, m)
2. Mass (kilogram, kg)
3. Time (second, s)
4. Temperature (kelvin, K)
5. Electric current (ampere, A)
6. Amount of substance (mole, mol)
7. Luminous intensity (candela, cd)

𝐃𝐞𝐫𝐢𝐯𝐞𝐝 𝐐𝐮𝐚𝐧𝐭𝐢𝐭𝐢𝐞𝐬
Derived quantities are physical quantities that can be defined in terms of fundamental quantities.

𝐄𝐱𝐚𝐦𝐩𝐥𝐞𝐬 𝐨𝐟 𝐃𝐞𝐫𝐢𝐯𝐞𝐝 𝐐𝐮𝐚𝐧𝐭𝐢𝐭𝐢𝐞𝐬
1. Area (square meter, m²)
2. Volume (cubic meter, m³)
3. Speed (meter per second, m/s)
4. Acceleration (meter per second squared, m/s²)
5. Force (newton, N = kg·m/s²)
6. Energy (joule, J = kg·m²/s²)
7. Power (watt, W = kg·m²/s³)
8. Pressure (pascal, Pa = kg/m·s²)
9. Density (kilogram per cubic meter, kg/m³)
10. Velocity (meter per second, m/s)
11. Momentum (kilogram-meter per second, kg·m/s)
12. Work (joule, J = kg·m²/s²)
13. Frequency (hertz, Hz = 1/s)
14. Electric charge (coulomb, C = A·s)
15. Resistance (ohm, Ω = kg·m²/s³·A²)

Hassan Mustafa Abdinur

𝐏𝐡𝐲𝐬𝐢𝐜𝐬 𝐟𝐨𝐫𝐦 𝐨𝐧𝐞

Date: 28 / 09 / 2025
Topic: Work

Definition
Work is the transfer of energy from one object to another through a force applied over a distance. It is a measure of the energy transferred or expended to achieve a particular task.

Mathematical Expression
W = F.d.cos(θ)

Where:
W = work done
F = force applied
d = distance over which the force is applied
θ = angle between the force and the direction of motion

Key Points
1. Energy transfer: Work involves the transfer of energy from one object to another.
2. Force and distance: Work requires both a force to be applied and a distance over which the force is applied.
3. Direction: The direction of the force and the direction of motion are important in determining the work done.

Types of Work
1. Positive work: Work done on an object when the force and displacement are in the same direction.
2. Negative work: Work done on an object when the force and displacement are in opposite directions.
3. Zero work: No work is done when the force and displacement are perpendicular or when there is no displacement.

Applications
1. Physics and engineering: Work is a fundamental concept in physics and engineering, used to analyze and design systems.
2. Energy conversion: Work is involved in the conversion of energy from one form to another.
3. Mechanical advantage: Work is used to calculate the mechanical advantage of machines and mechanisms.

Hassan Mustafa Abdinur

𝐏𝐇𝐘𝐒𝐈𝐂𝐒-𝐖𝐀𝐓𝐄𝐑 𝐖𝐀𝐕𝐄𝐒

Definition
Water waves are ripples or disturbances that travel through the surface of water, caused by wind, earthquakes, or other external forces.

Types of Water Waves
1. Wind-generated waves: Formed by wind friction on the water surface.
2. Tidal waves: Caused by gravitational forces of the moon and sun.
3. Seismic waves: Generated by earthquakes or underwater landslides.
4. Ocean swells: Large waves that form in the open ocean and travel long distances.

Characteristics
1. Amplitude: Height of the wave above the equilibrium level.
2. Wavelength: Distance between two consecutive wave crests.
3. Frequency: Number of waves passing a point per unit time.
4. Speed: Distance traveled by the wave per unit time.

Importance
1. Coastal erosion: Water waves can cause erosion and damage to coastlines.
2. Marine life: Water waves play a crucial role in shaping marine ecosystems.
3. Recreation: Water waves are essential for surfing, swimming, and other water sports.
4. Energy source: Water waves can be harnessed as a renewable energy source.

Hassan Mustafa Abdinur

RADIOACTIVITY AND IT'S COMPONENTS

Radioactivity is the natural process where an unstable atomic nucleus emits particles or energy to achieve greater stability. The main components, or types, of radioactivity are alpha (α) particles, beta (β) particles, and gamma (γ) rays, along with less common forms like neutron or proton emission and spontaneous fission. Alpha particles are positively charged helium nuclei, beta particles are electrons or positrons, and gamma rays are high-energy electromagnetic radiation.

DETAILS OF THE COMPONENTS OF RADIOACTIVITY

When an unstable nucleus undergoes radioactive decay, it releases energy and particles.
The primary types of emissions are:

1. Alpha (α) particles:
A stream of alpha particles, each consisting of two protons and two neutrons (a Helium-4 nucleus).

They are positively charged.

Due to their large size, they are easily blocked by materials like paper or clothing.

2. Beta (β) particles:
These are high-energy electrons (beta minus, β−) or positrons (beta plus, β+) that are ejected from the nucleus during beta decay.

They are negatively charged (electrons) or positively charged (positrons).

They can pe*****te materials like clothing and reach deeper into skin but can be stopped by denser materials such as aluminum.

3. GAMMA (γ) RAYS:
High-frequency electromagnetic radiation, similar to X-rays but with more energy.

They carry no charge and have no mass.

Because of their high energy, gamma rays are highly penetrating and can pass through most materials, requiring very dense substances like lead for effective shielding.

LESS COMMON FORMS OF RADIOACTIVITY
While alpha, beta, and gamma radiation are the most common, other forms of radioactive decay can also occur:

➡️Proton or neutron emission:
Release of protons or neutrons from the nucleus.

➡️Spontaneous fission:
The nucleus of a very large, heavy atom splits into two smaller nuclei, releasing energy.

➡️Neutrinos:
Emitted during beta decay, these are subatomic particles with very little mass and no charge.

Hassan Mustafa Abdinur

An airplane takes off and climbs at an angle of elevation of 30°. If its altitude from the ground is 2 km, find the distance it has traveled along its flight path.

Your Answer👇

A teacher entered the classroom and found the chair he was to sit on hung on the ceiling. He looked at the students and smiled. Without saying a word, he proceeded to the blackboard and wrote:

Test - 15 min, 30 marks.

Q1. Calculate the distance between the chair and the floor in centimeters (1 Mark).

Q2. Calculate the angle of inclination of the chair to the ceiling, and show your workings (1 Mark)

Q3. Write the name of the student who hung the chair on the ceiling and the friends who helped him. (28 Marks).

“The teacher caught the student who hung the chair.” ✅😂😂😂

𝗦𝗜𝗗𝗘𝗘 𝗕𝗔𝗬 𝗔𝗤𝗢𝗢𝗡𝗬𝗔𝗛𝗔𝗡𝗞𝗜𝗜 𝗛𝗢𝗥𝗘 𝗪𝗔𝗤𝗧𝗜𝗚𝗔 𝗨𝗚𝗔 𝗙𝗔𝗔'𝗜𝗜𝗗𝗔𝗬𝗦𝗔𝗡 𝗝𝗜𝗥𝗘𝗘𝗡?

Caalim magaciisa la oran jiray 𝐂𝐚𝐚𝐦𝐢𝐫 𝐛𝐢𝐧𝐮 𝐂𝐚𝐛𝐝𝐢-𝐐𝐚𝐲𝐬, kana mid ahaa dadkii taabicitiinta la dhihi jiray ee saxaabada soo gaaray, ayaa laga sheegaa in uu maalin maalmaha ka mid ah nin soo booqday isagoo wax 𝐚𝐤𝐡𝐫𝐢𝐬 𝐤𝐮 𝐡𝐨𝐰𝐥𝐚𝐧, kadibna waxaa la hadlay ninkii soo booqday, balse sheekhii kamuu helin wax jawaab ah, markuu ninkii waydiiyay sababta uu ula hadli waayay wuxuu ku sheekhii ku jawaabay: "𝐀𝐚𝐧 𝐤𝐮𝐥𝐚 𝐡𝐚𝐝𝐥𝐞𝐞 𝐡𝐨𝐫𝐭𝐚 𝐜𝐚𝐝𝐜𝐞𝐞𝐝𝐝𝐚 𝐣𝐨𝐨𝐣𝐢"

Hadalkan uu sheekha ku jawaabay wuxuu marag u yahay in culimadii (aqoonyahanadii) h**e ay waqtigooda si dhab ah uga faa'ideysan jireen, aysan ogolaan jirin wada sheekaysi aan waxba laga faa'ideyn.

𝗔𝗻𝗮𝗴𝘂𝘀𝗲 𝗺𝗮𝗮𝗻𝘁𝗮 𝗸𝗮𝗺𝗮 𝗳𝗮𝗮'𝗶𝗶𝗱𝗲𝘆𝘀𝗮𝗻𝗼 𝘄𝗮𝗾𝘁𝗶𝗴𝗲𝗲𝗻𝗶𝗶 𝗾𝗮𝗮𝗹𝗶𝗴𝗮 𝗮𝗵𝗮𝗮!!
𝙰𝚕𝚕𝚎 𝚑𝚊 𝚒𝚗𝚊𝚐𝚊 𝚍𝚑𝚒𝚐𝚘 𝚔𝚞𝚠𝚘 𝚠𝚊𝚚𝚝𝚒𝚐𝚘𝚘𝚍𝚊 𝚔𝚊 𝚏𝚊𝚊'𝚒𝚒𝚍𝚎𝚢𝚜𝚝𝚊🤲

𝐆𝐚𝐥𝐚𝐛 𝐰𝐚𝐧𝐚𝐚𝐠𝐬𝐚𝐧~𝐒𝐚𝐚𝐱𝐢𝐢𝐛𝐲𝐚𝐚𝐥☕📖

𝗪/𝗤: Shariif Hassan Mustafa Abdinur [Gurey]