Answer:
3. When energy is used, it can transform to new types but can never disappear.
Explanation: it can transform into heat, light, ect and will never disapear unlessed turned of.
9 because speed=distance/ time
Answer:
According to Einstein's famous equation, matter can convert into energy (and viceversa) as follows:
where
E is the energy
m is the mass
c is the speed of light (
)
Given the huge value of 
, we see that even a tiny amount of matter is able to release a huge amount of energy, when the whole mass is converted into energy. This is precisely what happens in nuclear reactions. For example, in the process of nuclear fusion (that occurs in the core of the stars), two light nuclei fuse together into a heavier nucleus. The mass of the final nucleus is lower than the total mass of the initial nuclei, so part of the mass has been converted into energy according to the equation above: this is why the amount of energy produced by stars is so big.
Answer: True
Explanation: Metamorphism is the changing of rocks by heat and pressure. During this process, rocks change either physically and/or chemically. They change so much that they become an entirely new rock. Figure 4.22: The platy layers in this large outcrop of metamorphic rock show the effects of pressure on rocks during metamorphism.
