Explanation

• First man who travelled in Space was Yuri Gagarin in 1961.
• Yuri Gagarin was a Soviet pilot and cosmonaut.
• He aboard the first successful crewed spaceflight, became the first human to journey into outer space.

Additional information:

• First man who Walk in Space was Alexei Leonov in 1965.
• First man who Walk on Moon was Neil Armstrong in 1969.

Last verified on 10-03-2026

Explanation

Very high frequency is the ITU designation for the range of radio frequency electromagnetic waves from 30 to 300 megahertz,

with corresponding wavelengths of ten to one meter.

ND17-7-2023

Explanation

• The pitch of a sound wave depends on its frequency.
• Pitch tells us whether a sound is high or low.
• Higher frequency → higher pitch (e.g., whistle).
• Lower frequency → lower pitch (e.g., bass drum).
• Frequency is measured in Hertz (Hz).

Last verified on 11-08-2026

Explanation

• The law of universal gravitation was proposed by Isaac Newton.
• He introduced it in 1687 in his famous book Principia.
• It explains that every object attracts every other object.
• The force depends on mass and distance.

Last verified on 27-04-2026

Explanation

• Ozone (O₃) is mainly found in the Stratosphere, called the ozone layer.
• It absorbs harmful ultraviolet (UV) radiation from the sun, protecting life on Earth.
• Located roughly 15–35 km above the Earth’s surface.

Last verified on 17-01-2026