Explanation

Planets move around the Sun because of gravity.

- The Sun's gravitational force pulls planets toward it.

- Planets have forward motion (inertia).

- The balance between gravity and forward motion keeps them in orbit.

Last updated 06 Nov 2026 by NA

Explanation

• Manganese dioxide acts as a catalyst in the decomposition of hydrogen peroxide.
• It increases the reaction rate without being permanently consumed.
• Water and oxygen are produced.

Last verified on 07-11-2026

Explanation

• An electric fan uses electrical energy to rotate its blades, producing mechanical motion.
• This mechanical energy helps in circulating air to provide cooling.

Last verified on 07-11-2026

Explanation

• The SI unit of energy is the Joule (J).
• It is the unit of energy, work, and heat.

Additional information:

• 1 Joule (J) = 1 Newton × 1 meter
• Calorie – 1 cal = 4.184 J
• Kilowatt-hour (kWh) – 1 kWh = 3.6 × 10⁶ J
• Electronvolt (eV) – 1 eV ≈ 1.602 × 10⁻¹⁹ J
• Erg (CGS unit) – 1 erg = 10⁻⁷ J

Last verified on 17-01-2026

Explanation

Newton's second law relates force, mass and acceleration.

Acceleration = Force ÷ Mass = 20 ÷ 5 = 4 m/s².

Last verified on 07-11-2026