Answer:
A first-class lever: fulcrum is between input and output force; second-class lever: output force is between input force and fulcrum; third-class lever: input force is between fulcrum and output force
Answer:
false, because a phase change occurs physical changes when matter changes its energy state.
To demonstrate the number of protons neutrons and electrons.
We call "terminal velocity" the constant speed of a falling body
when it is no longer accelerating.
We know that if a body is not accelerating, then the net force
on it is zero.
From the question, we know that the downward force of gravity
on the skydiver is 800 N.
If the 800 N downward plus the air resistance upward add up
to zero, then the air resistance upward must also be 800 N.
Both balls hit the ground at the same time.
We've known this fact for about 500 years (since Galileo),
and we've known WHY for about 300 years (since Newton).
