Aadya Isai

Stapelia (family Apocynaceae, subfamily Asclepiadoideae) is a group of stem-succulent plants native to southern Africa. These plants are known for producing large, fleshy, star-shaped flowers that often mimic the appearance and scent of rotting meat.

Key scientific features:

• Morphology:

Stapelia plants lack true leaves and instead have photosynthetic, four-angled or cylindrical stems adapted for arid environments.

The flowers typically have five lobes, covered with trichomes (fine hairs) that give them a furry or velvety texture.

• Odour chemistry:

Definition:

Electric current is the flow of electric charge.

Here’s the idea in simple, clear words:

• Every object has tiny charged particles (electrons).

• When these electrons start moving in one direction through a wire, we say an electric current is flowing.

• The faster the charge moves, the higher the current.

What is a Circuit?

A circuit is a complete, unbroken loop that allows electric charges (electrons) to move continuously.

Electricity can only flow if the path starts at the energy source and comes back to it.

Key parts of a circuit:

• Energy source – a battery or power supply that provides the push for electrons.

• Conducting path – wires that allow electrons to travel.

Definition:

Conductor:

A conductor is a material that allows electric charge to flow through it easily.

Insulator:

An insulator is a material that does not allow electric charge to flow through it easily.

Examples:

Definition - A coulomb meter is a device used to measure the amount of electric charge an object has, usually in coulombs (C).

How does it measure?

A coulomb meter is a device used to measure the amount of electric charge an object has, usually in coulombs (C).

Coulomb and ampere:

A coulomb is a measure of electric charge.

Think of electric charge like tiny invisible “electric bits” that can move through wires or build up on objects.

Definition of positive and negative charges:

Positive and negative charges are two opposite types of electric charge found in matter. A positive charge occurs when an object has fewer electrons than protons, and a negative charge occurs when an object has extra electrons. These charges create electrostatic forces that make objects attract or repel each other.

Electric force:

Electric forces are the interactive forces that arise between objects due to their electric charge. These forces follow the principles of Coulomb’s Law, which states that:

• Like charges repel.

  Two positively charged or two negatively charged bodies experience a repulsive force.

  
  

1. Static electricity builds up

   • Your body, clothes, or other objects can gather extra electric charges.

   • These charges are mostly electrons (tiny negatively charged particles).

     
     

2. Voltage difference forms

   • When there’s a lot of extra charge in one place, there’s a strong “push” trying to move the electrons to a place with fewer charges.

   • This push is called voltage.

     
     

Introduction:

Static electricity is the buildup of electric charge on the surface of an object. Some materials allow these charges to move easily, while others trap them in place. Materials that let electric charges flow freely are called conductors.

Conductors of Static Electricity:

• Metals: Metals like silver, copper, aluminum, and iron are excellent conductors. They have free electrons that can move easily, allowing charges to spread quickly.

• The Human Body: The human body is mostly water, which contains dissolved salts such as sodium and potassium. These salts break into ions—tiny charged particles that can move through the water in your tissues. This is why your body can carry and transfer static electricity. For example, when you walk on a carpet, electrons may build up on your body. Touching a metal doorknob lets these charges flow, often creating a small spark.

• Water: Pure water is a poor conductor, but most natural…

1. Introduction:

   • Definition - Static electricity is an imbalance of electric charges within or on the surface of a material. The charge remains until it can move away as an electric current or by electrical discharge.

   
   

2. Formation and Discharge of Static Electricity:

   Static electricity happens when tiny particles called electrons move from one object to another, usually when two things rub together or touch and separate.

   
   

   Here’s the explanation in simple but strong, clear words:

   
   

   • Every object has tiny electric charges inside it.

• The principle of moments says a system is in equilibrium when clockwise moments and anticlockwise moments are equal.

• A moment is a turning force that tries to rotate an object around a pivot.

• It is calculated using M = F × d, where F is the force and d is the perpendicular distance from the pivot.

• This principle is used in everyday tools like levers, seesaws, and similar devices to balance forces or lift heavy loads.

• The principle only works when the object is in equilibrium (not moving or rotating).

• Moments depend on direction (clockwise or anticlockwise), so you must keep track of which way each force tries to turn the object.

Scalar Quantities

A scalar quantity does not tell us the direction. You can describe it with just a number and a unit.

Examples:

• Mass – 5 kg

• Time – 10 second

• Temperature – 25°C

The turning effect of a force is the effect that makes an object rotate or turn around a fixed point when a force is applied.

why?

Because when a force is applied away from a fixed point, it doesn’t just push the object—it also makes it rotate around that point.

Here’s why:

• The part of the object closer to the fixed point (pivot) stays almost still.

• The part where the force is applied tries to move.

Liquid Pressure

• Liquid pressure is the force that a liquid exerts on the walls or bottom of its container.

• It is caused by the weight of the liquid and acts in all directions.

• The deeper you go, the greater the pressure — because more liquid is above that point.

• Example: When you dive deeper into a swimming pool, you feel more pressure on your ears — that’s liquid pressure increasing with depth.

Gas Pressure

Sometimes we want high pressure and sometimes we want low pressure. Here is how high and low pressure help us.

How does pressure increases/ decrease and why?

Pressure increases when the force becomes stronger or the area becomes smaller, because that changes how the force spreads across a surface. When you increase the force, you’re pushing harder, so each part of the surface feels more force. When you decrease the area, the same force is concentrated in a smaller space, which also increases pressure.

For example, if you press a balloon on one nail, it bursts easily because all your force is acting on the tiny tip of the nail—small area means high pressure. But if you press the balloon on a bed of nails, it doesn’t burst, because your force spreads over many nails, making the total area larger and the pressure lower.

Pressure decreases when the force becomes…

Definition

Pressure is the amount of force exerted per unit area on a surface. It tells us how concentrated a force is — whether it’s spread out or focused on a small point.

Formula:

Pressure = Force /Area

• Force (F) is measured in Newtons (N).

• Area (A) is measured in square meters (m²).

Flash card about resistance

1. Definition

• Mass: The amount of matter in an object.

• Weight: The force of gravity acting on an object.

2. Unit

• Mass: Kilogram (kg), gram (g)

• Weight: Newton (N)

Conservation of momentum

Vector quantity, magnitude and direction.

Flash card - momentum

Why is “momentum mass into velocity”?

When scientists wanted to describe motion, they realized that just saying “fast” (velocity) wasn’t enough. A small pebble moving at 10 m/s doesn’t have the same impact as a truck moving at 10 m/s. At the same time, just knowing “heavy” (mass) wasn’t enough either—a huge boulder sitting still doesn’t cause any effect, while a smaller tennis ball moving quickly can hit and sting.

What matters is both together: the amount of matter (mass) and the speed plus direction of motion (velocity). That’s why momentum is defined as mass × velocity—it captures the full story of motion.

what is momentum?

Momentum is a measure of how much motion an object has.

It depends on two things:

Items completed - what is momentum, formula, why mass and velocity makes momentum (deep research with examples).

Flash card about temperature

Temperature

Keywords - Definition, units, measurement tools, Extreme applications.

Gravity is a natural force that pulls everything toward everything else. On Earth, it pulls us, the air, and objects toward the ground, which is why we don’t float away.

In simple words: gravity is what keeps your feet on the ground and makes things fall when you drop them.

What does it do?

• It keeps planets orbiting the Sun. Without gravity, Earth would drift into space.

• It holds the Moon around Earth, making tides in the oceans.

• It pulls objects together, helping stars and planets form.

Flash cards

1. cardiac arrest

2. Volume, density, mass, and their differences