Question

define galaxy.....................and pulley​

Answer 1

Answer:

Galaxy is a system of millions or billions of stars, together with gases and dust held together by gravitational attraction.

Pulley is a wheel with a grooved rim around which a cord passes, which acts to change the direction of a force applied to the cord and is used to raise heavy weights.

Explanation:

Answer 2

Answer:

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Galaxy

$\blue\implies$A galaxy is a huge collection of gas, dust, and billions of stars and their solar systems. A galaxy is held together by gravity. Our galaxy, the Milky Way, also has a supermassive black hole in the middle. When you look up at stars in the night sky, you're seeing other stars in the Milky Way.

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Pulley

$\blue\implies$A pulley is a wheel on an axle or shaft that is designed to support movement and change of direction of a taut cable or belt, or transfer of power between the shaft and cable or belt. ... The drive element of a pulley system can be a rope, cable, belt, or chain.