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

Explanation

• Inertia is the resistance of an object to a change in its state of motion.
• Greater mass means greater inertia.

Last verified on 07-11-2026

Explanation

• The direction of velocity continuously changes during circular motion.
• Centripetal acceleration acts toward the centre of the circular path.
• Constant speed does not mean constant velocity.

Last verified on 07-11-2026