Explanation

A velometer measures the velocity of airflow in ducts or open spaces.

Commonly used in HVAC systems and meteorological studies.

Explanation

Mass of an object does not change regardless of its location, including in space.

Weight, however, depends on gravity and can change in space.

Explanation

Newton's Law of Gravitation states that every particle attracts every other particle in the universe with a force

That is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.

Explanation

Radioactivity was discovered by Henri Becquerel in 1896.

They discovered radioactivity proving that the uranium emitted radiation without an external source of energy such as the Sun

Marie Curie with her husband Pierre Curie, coined the term radioactivity.

In 1903, Henry Becquerel shared the Nobel Prize for Physics with Pierre and Marie Curie

Ernest Rutherford did many experiments studying the properties of radioactive decay (alpha, beta, and gamma)

Explanation

Opaque objects form sharp and dark shadows because they block all light from passing through, creating a clear and defined shadow.

Explanation

A nutcracker works as a lever to multiply force.

It helps crack hard nuts with less effort.

Explanation

Frequency (f) is inversely proportional to wavelength (λ):

f ∝ 1/λ => f = k/λ => k = fλ

Given: f1 = 100 kHz, λ1 = 3000 m; λ2 = 500 m

k = f1λ1 = f2λ2

100 kHz × 3000 m = f2 × 500 m

f2 = (100 kHz × 3000 m) / 500 m

= 600 kHz

Explanation

CNG stands for Compressed Natural Gas

Methane is the main component of CNG 

the modern use of CNG as a fuel source began in the 1930s,

American physicist Dr. J.P. Farley discovered that natural gas could be compressed to a high-pressure 

natural gas became a transport fuel during the First World War

Explanation

A screw gauge measures very small lengths or thicknesses accurately (like wire diameter or sheet thickness).

It works using a rotating screw mechanism that gives precise readings up to 0.01 mm.

Explanation