Answer:
The arrow was moving at 16.2 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 v, we get:
The arrow was moving at 16.2 m/s
Explanation:
Extrusive rocks may have a few grains that are large enough to see, but most of them will be too small to see individual minerals. ... The individual mineral grains are almost too small to see. Some extrusive rocks cool so quickly that they do not form any grains. Instead, they form a natural glass.
Answer:
B) Electrons and protons
Explanation:
Each proton has a positive charge, and each electron has a negative charge. If the atom is electrically neutral, there must be the same number of electrons and protons.
A) and C) are wrong. Neutrons have no charge, so they can't counteract that of the protons or the electrons.
D) is wrong. The atomic number is the number of protons, and the mass number is the number of protons plus neutrons. The neutrons can't counteract the charge of the protons,
