Explanation

• The amplitude of a sound wave determines its loudness.
• Greater amplitude generally produces a louder sound.
• While smaller amplitude produces a quieter sound.

Additional information:

• Frequency: Determines pitch (high or low sound).
• Wavelength: The distance between two consecutive points in the same phase, such as two crests.

Last verified on 15-10-2026

Explanation

• A velocity–time graph shows how velocity changes with time.
• The slope gives acceleration.
• The area under the graph represents motion covered.
• It connects velocity with displacement.

Last verified on 22-05-2026

Explanation

• The speed of sound is generally maximum in solids.
• Because their particles are closely packed and elastic forces transmit vibrations rapidly.

Additional information:

• Solids: Sound generally travels fastest, e.g., Steel: 5,000–6,000 m/s
• Liquids: Sound travels slower than in most solids, e.g., Water: 1,480 m/s
• Gases: Sound travels slowest under ordinary conditions, e.g., Air at 20°C: 343 m/s

Last verified on 15-10-2026

Explanation

• Newton’s First Law of Motion is also called the Law of Inertia.
• It states that an object remains at rest or continues moving at a constant velocity in a straight line unless acted upon by an unbalanced external force.
• Inertia is the tendency of an object to resist changes in its state of rest or motion.
• Proposed by: Sir Isaac Newton in Principia Mathematica (1687).

Last verified on 15-10-2026

Explanation

• Earth is called the Blue Planet.
• About 71% of Earth's surface is covered by water.
• Water makes Earth appear blue from space.
• Earth is the third planet from the Sun.
• Earth’s natural satellite is the Moon

Last updated: NA on 26-09-2026