Answer:
Almost all machines require energy to offset the effects of gravity, friction, and air/wind resistance. Thus, no machine can continually operate at 100 percent efficiency.
A spring scale measures weight because <span>It works by Hooke's Law, which states that the force needed to extend a </span>spring<span> is proportional to the distance that </span>spring<span> is extended from its rest position. Therefore, the </span>scale<span> markings on the </span>spring<span> balance are equally spaced. A </span>spring scale<span> can</span>not measure mass<span>, only </span>weight<span>. hope that helped</span>
Answer:
Nicolaus Copernicus
Explanation:
With the development of the heliocentric model by Nicolaus Copernicus in the 16th century, the Sun was believed to be the center of the Universe, with the planets (including Earth) and stars orbiting it.
Answer:

Explanation:
Where E is the magnitude of electric field...
k is called Columb's Constant. It has a value of 8.99 x 109 N m2/C2.
Qs is the magnitude of the source charge...
and r is the magnitude of distance between source and target...
(When electron comes to rest Δt the magnitude of Electric field E become zero momentarily but later achieves the maximum value...)