Question: How fast was the arrow moving before it joined the block?
Answer:
The arrow was moving at 15.9 m/s.
Explanation:
The law of conservation of energy says that the kinetic energy of the arrow must be converted into the potential energy of the block and arrow after it they join:

where
is the mass of the arrow,
is the mass of the block,
of the change in height of the block after the collision, and
is the velocity of the arrow before it hit the block.
Solving for the velocity
, we get:

and we put in the numerical values
,



and simplify to get:

The arrow was moving at 15.9 m/s
<h2>
Answer:2.65 seconds</h2>
Explanation:
Let
be the acceleration.
Let
be the initial velocity.
Let
be the final velocity.
Let
be the time taken.
As we know from the equations of motion,

Given,


What Newton discovered is that gravity extends throughout the universe.
<h3>What is gravity?</h3>
The term gravity refers to the force that acts on a body in the universe. It is gravity that makes an object to fall when it is thrown up. The force of gravity acts on every object in the universe and it extends through the universe.
Humans have always known about gravity when they fall from a height and when they threw things up. However, human did not know that gravity extends throughout the universe.
Thus, what Newton discovered is that gravity extends throughout the universe.
Learn more about gravity:brainly.com/question/4014727
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