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:
The SI unit for electric chargeis the C (which is the abbreviation of Coulomb}
Explanation:
The SI unit for electric chargeis the Coulomb. The letter used is the C.
1 C = 1 As
A best describes magnetism
Answer:
8 V
Explanation:
There is no resistance between the left legs of voltmeters 2 and 3 and there is no resistance between the right legs of voltmeters 2 and 3. They are measuring the same voltage.
