Explanation

The weight of an object at the center of the Earth is the same as its weight on the surface.

This might seem counterintuitive, but it's because the gravitational force acting on the object is proportional to the distance from the center of the Earth.

At the center, the distance is zero, but the gravitational force is also zero because the object is surrounded by equal amounts of mass in all directions.

Explanation

In deep space far from massive objects, the gravitational pull becomes negligible, effectively making gravity zero.

This is why astronauts experience weightlessness in such regions.

Explanation

At a radio station, a person speaks into a microphone, which converts sound waves into electrical signals.

These signals are then processed and transmitted through an antenna to reach listeners.

Explanation

When moving with constant velocity, there is no net acceleration acting on the body.

Therefore, the apparent weight remains the same as actual weight — not changed.

Explanation

In a reversible process, the entropy of the system remains constant. 

 A key characteristic of a reversible process is that it can be reversed without leaving any net change in the system or its surroundings, including the entropy. 

Explanation

Asteroids are also called "minor planets".

They are small, rocky bodies that orbit the Sun, often between Mars and Jupiter.

They are considered remnants from the formation of the solar system and are not large enough to be classified as a planet. 

"asteroids" (possibly what "altereds" was meant to be)

Explanation

Static electricity is used in electrostatic precipitators to remove smoke and dust particles from gases in smokestacks.

Charged particles are attracted to plates with opposite charge, cleaning the air before release.

Explanation

Edwin Hubble's observations of galaxies moving away from each other, encapsulated in Hubble's Law, were crucial in suggesting that the universe is expanding.

This observation strongly supported the idea that the universe had a singular, hot, dense origin.

Georges Lemaître, in 1927, was the first to propose the idea of the universe expanding from a "primeval atom," a concept that would later form the basis of the Big Bang theory.

Explanation

A periscope is used to see objects above the eye level, commonly in submarines or behind obstacles.

It uses mirrors or prisms to reflect light down to the viewer’s eyes.

Explanation