C, they didn't know any better
Answer:
a,e,d
Explanation:
i got it right when i was doing study island
There are 8 hydrogen atoms
Humans rely on photosynthesis to generate food as well as provide energy for heating, lighting, and electricity.
Answer:
Time = 0.55 s
Height = 8.3 m
Explanation:
The ball is dropped and therefore has an initial velocity of 0. Its acceleration, g, is directed downward in the same direction as its displacement,
.
The dart is thrown up in which case acceleration, g, acts downward in an opposite direction to its displacement,
. Both collide after travelling for a time period, t. Let the height of the dart from the ground at collision be
and the distance travelled by the ball measured from the top be
.
It follows that
.
Applying the equation of motion to each body (h = v_0t + 0.5at^2),
Ball:
(since
.)

Dart:
(the acceleration is opposite to the displacement, hence the negative sign)

But




The height of the collision is the height of the dart above the ground,
.



