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
Silver: bonds with other atoms because of the weak forces of the valence electrons
FALSE - The strong forces of the valence electrons is actually the reason why silver bonds with other atoms.
Water: bonds allow for liquid state at room temperature and prevent conduction
FALSE - Water is a good conductor.
Carbon: bonds with other atoms through strong shared electrical bonds
TRUE - Carbon shares covalent bonds with other atoms.
Niobium: bonds allow for a strong conductivity found in stainless steel
FALSE - Iron and Carbon make up steel.
Answer:
I think decreases inversely
Explanation:
the third
Answer:
A and B are correct both are correct
Answer:
E = 13.2 kWh
, Cost = $ 10.8
Explanation:
We can look for the consumed energy from the expression of the power
P = W / t
The work is equal to the variation of the kinetic energy, for which
P = E / t
E = P t
look for the energy consumed in one day and multiply by the days of the month in the month
E = 110 4 30
E = 13200 W h
E = 13.2 kWh
the cost of this energy is
Cost = 0.9 12
Cost = $ 10.8
