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
Answer:
All steps are 20 * 100 (break the rest into appropriate pieces)
You can multiply as follows
(2000) * ((3 * 60) + (2 * 60) + 60)
V = 2000 * 6 * 60) = 720,000 cm^3 = .72 m^3
.72 m^3 * 2400 kg / m^3 = 1728 kg
When g=a, that means everything on earth fall at the same rate.
<h3>Why does everything fall to the earth at the same rate?</h3>
As such, all objects free fall at the same rate regardless of their mass. Because the 9.8 N/kg gravitational field at Earth's surface causes a 9.8 m/s/s acceleration of any object placed there, we often call this ratio the acceleration of gravity.
<h3>Why is gravity equal to acceleration?</h3>
When objects fall to the ground, gravity causes them to accelerate. Acceleration is a change in velocity, and velocity, in turn, is a measure of the speed and direction of motion. Gravity causes an object to fall toward the ground at a faster and faster velocity the longer the object falls.
Know more about gravity here
brainly.com/question/4014727
#SPJ2