Explanation

• In a vacuum, both balls reach the ground at the same time because there is no air resistance.
• All objects fall with the same gravitational acceleration (9.8 m/s²).
• The mass of an object does not affect its falling speed in a vacuum.
• This principle was demonstrated by Galileo Galilei.

Verified & Updated

Explanation

• Light Year is the distance that light can travel in one year.
• The distance light travels in one year is known as light year.
• 1 light year is equal to 9.5 x 10¹²km.

Last verified on 30-03-2026

Explanation

• The Troposphere contains about 75% of the atmosphere's mass.
• It is the lowest layer of Earth's atmosphere.
• Altitude Range: About 8 km at poles to 15–18 km at equator.
• Main Gases: Nitrogen (78%), Oxygen (21%), and other gases.ev

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Explanation

• In a nuclear reactor, energy is produced due to a controlled chain reaction.
• A controlled chain reaction releases energy steadily and safely.
• Control rods are used to regulate the number of neutrons and prevent excessive reactions.
• This controlled process is used to generate electricity in nuclear power plants.

Additional information:

• An uncontrolled chain reaction occurs in nuclear bombs.

Last verified on 11-07-2026

Explanation

Formula:  

Mean = Sum of observations / Number of observations  

Given:  

Mean = 50  

Number of observations = 10  

Sum of observations = Mean _ Number of observations  

= 50 _ 10  

= 500

Last verified on 11-07-2026