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:
a) a = 1,865 m / s² and b) t = 8.1 s
Explanation:
a) Let's use Newton's second law to find acceleration, we can work the equation in scalar form because displacement and force have the same direction
F = m .a
a = F / m
a = 8.02 10² /4.3 10²
a = 1,865 m / s²
b) We use kinematic relationships in one dimension
vf = vo + at
vf = 0 + a t
t = vf / a
t = 15.1 / 1.865
t = 8.1 s
Answer:
The number of molecules displaced in a vibration makes the amplitude of a sound.
I think the answer is 2283g
