check the pictures(2 pictures)check the pictures(2 pictures)check the pictures(2 pictures)
The correct answer is C. luster refers to how much light is in an object or how much reflects off. hope this helps, have an amazing day :)
Answer:
It is an instrument which increases the amount of force available to a single hypothetical person.
Examples;
Levers, pulleys are force magnifiers.
Answer:

Explanation:
Since work done is in the form of potential energy, we will use the formula of potential energy here.
We know that,
<h3>P.E. = mgh </h3>
Where,
m = mass = 20 kg
g = acceleration due to gravity = 10 m/s²
h = vertical height = 20 m
So,
<h3>Work done = mgh</h3>
Work done = (20)(10)(20)
Work done = 4000 joules
Work done = 4 kJ
![\rule[225]{225}{2}](https://tex.z-dn.net/?f=%5Crule%5B225%5D%7B225%7D%7B2%7D)