Explanation

• Phosphorus (P), Potassium (K), and Nitrogen (N) are three essential macronutrients for plant growth.
• It is also referred to as "NPK".
• They play critical roles in various plant processes, including photosynthesis, root development, and cell growth.

Last verified on 17-03-2026

Explanation

• A solid has both a definite shape and a definite volume.
• The particles in solids are tightly packed and only vibrate in fixed positions.
• Examples include iron, wood, stone, and ice.

Additional information:

• A liquid has a definite volume but no definite shape.
• A gas has neither definite shape nor definite volume.

Explanation

• Freezing is the process by which a liquid changes to a solid.
• It is the reverse of melting, which is the process by which a solid changes to a liquid.

Last verified on 13-03-2026

Explanation

• The invention of the Lever is attributed to Archimedes.
• The lever was first described in 260 B.C.E. by Archimedes.

Last verified on 13-03-2026

Explanation

• The freezing point of water is 0°C (32°F), where water changes from liquid to solid.
• The melting point is also 0°C, where ice changes from solid to liquid.
• Freezing and melting are opposite processes occurring at the same temperature.

Last verified on 13-03-2026

Explanation

• Liquids have no fixed shape but have a fixed volume.
• Particles are close together but can slide past each other, allowing the liquid to flow.

Additional information:

• Solid: Are tightly packed and stay in a fixed position
• Gas: Are widely spaced and move freely in any direction

Last verified on 13-03-2026

Explanation

• An inclined plane is a flat surface tilted at an angle to help move objects up or down with less effort.
• It reduces the force needed compared to lifting vertically.
• Mechanical advantage = distance along incline ÷ vertical height.

Last verified on 08-03-2026

Explanation

• Weight depends on gravitational force acting on mass.
• The Moon’s gravity is about 1/6th of Earth’s, so your weight decreases.
• Your mass remains the same, only weight changes.

Additional information:

• Weight change occurs due to difference in gravity.
• Mass is constant everywhere in the universe.

Last verified on 08-03-2026

Explanation

• Weight is the force of gravity acting on an object's mass.
• It depends on mass of the object and gravitational acceleration (g).
• Formula: Weight (W) = Mass × Gravity (W = m × g)

Additional information:

• Earth: g ≈ 9.8 m/s²
• Moon: g ≈ 1.6 m/s² (weight is less)

Last verified on 08-03-2026

Explanation

• Frictional force arises when two surfaces slide or move against each other.
  • It opposes the motion and can generate heat.
  • Friction is essential in walking, driving, and machine operation.

Last verified on 08-03-2026