Sports Biomechanics: Levers, Rotation, Newton’s Laws
Third-Class Lever Example: Knee Extension
Q1: An example of a third-class lever is knee extension (like kicking a ball), where the force is between the fulcrum and load. The knee joint is the fulcrum (the pivot point where the lower leg rotates), the quadriceps tendon, inserting on the tibial tuberosity, provides the effort in the middle, and the leg and foot (plus any ball) form the load at the far end.
Landing Technique: Shock Absorption in Gymnastics
Q2: Gymnasts bend their knees and flex their
Read MoreCore Concepts in Radiation Physics, Solar Cells, and Electromagnetism
Radiation Interaction with Matter
1. Alpha (α) Particles
- Heavy, positively charged particles.
- Interact strongly with matter, leading to high ionization.
- Lose energy quickly and stop within a few centimeters of air.
2. Beta (β) Particles
- Fast-moving electrons.
- Moderate interaction, resulting in moderate ionization.
- Can travel a few meters in air.
3. Gamma (γ) Rays
- Electromagnetic waves (no mass, no charge).
- Weak interaction, causing low ionization.
- Travel long distances and penetrate deeply.
Penetrating Power
Read Moreਪੰਜਾਬੀ ਵਿਆਕਰਨ: ਧੁਨੀ, ਅੱਖਰ, ਲਗਾਂ ਅਤੇ ਸ਼ਬਦ ਬਣਤਰ ਸਿੱਖੋ
ਪੰਜਾਬੀ ਵਿਆਕਰਨ ਦੇ ਮੂਲ ਅੰਗ: ਧੁਨੀ ਅਤੇ ਅੱਖਰ ਬੋਧ
ਧੁਨੀ ਬੋਧ (Phonology) ਅਤੇ ਅੱਖਰ ਬੋਧ (Orthography) ਪੰਜਾਬੀ ਵਿਆਕਰਨ ਦੇ ਪਹਿਲੇ ਅਤੇ ਮਹੱਤਵਪੂਰਨ ਭਾਗ ਹਨ। ਇਸ ਵਿੱਚ ਭਾਸ਼ਾ ਦੀਆਂ ਸਭ ਤੋਂ ਛੋਟੀਆਂ ਇਕਾਈਆਂ—ਧੁਨੀਆਂ ਅਤੇ ਉਹਨਾਂ ਨੂੰ ਲਿਖਣ ਲਈ ਵਰਤੇ
Read MoreCalculating Gravitational Force and Work on a Spacecraft
Problem Q2: Spacecraft Dynamics in the Earth-Moon System
At a certain instant, the Earth, the Moon, and a stationary 1250-kg spacecraft lie on the vertices of an equilateral triangle whose sides are 3.84 x 105 km in length.
Given Parameters
- Mass of the Earth ($M_E$): 5.97 x 1024 kg
- Mass of the Moon ($M_M$): 7.35 x 1022 kg
- Total Mass ($M_{Total}$): 6.04 x 1024 kg (Verification required)
The simplest way to approach this problem is to find the gravitational force between the spacecraft and the center of
Read MoreQuantum Mechanics Fundamentals: 16 Key Concepts Explained
Core Principles of Quantum Mechanics
The No-Cloning Theorem
The no-cloning theorem states that it is impossible to create an exact copy of an arbitrary unknown quantum state. This is because quantum mechanics is linear and unitary; any operation that clones one state would necessarily distort another. Only orthogonal states (like |0⟩ and |1⟩) can be perfectly distinguished and copied.
The Copenhagen Interpretation
According to the Copenhagen interpretation, the wave function represents the probability
Read MoreEssential Physics Laws, Units, and Core Concepts
Fundamental Laws and Conservation Principles
- Newton’s First Law: An object stays in uniform motion unless a net force acts (if net force = 0, motion remains unchanged).
- Newton’s Second Law: Acceleration is proportional to net force and inversely proportional to mass.
- Newton’s Third Law: Forces come in equal and opposite pairs (action and reaction).
- Conservation of Energy: Total mechanical energy remains constant if no non-conservative forces act.
- Conservation of Momentum: Total momentum stays constant