Earthquakes produce three types of seismic waves: primary waves, secondary waves, and surface waves. Each type moves through materials differently. In addition, the waves can reflect, or bounce, off boundaries between different layers.
three key points:
1. they all change the earth by shifting plates in different ways.
2. these waves lead to our plates form today, which are always changing.
3. even the smallest earthquakes make the slightest changes to our ground. and many happen in just a day! we just never feel it.
Answer:
23 J
Explanation:
According to the law of conservation of energy, the total heat given off to the surroundings by a refrigerator is equal to the work done by the refrigerator and the heat removed from the inside of the refrigerator.
So we can write:
where
is the heat removed from the cold reservoir (the inside of the refrigerator)
W is the work done
is the work released into the hot reservoir (the surroundings)
Here we have:
(heat removed from the inside of the refrigerator)
(heat released into the surroundings)
Solving the equation for W, we find the work done:
Answer:2
Explanation:
Given
and 
and 
are the acceleration of 1 and 2
Suppose T is the Tension
then for block 2
For block 1
equate 1 and 2
where 
thus we can see that a is less than g
therefore 
Answer:
-18
Explanation:
acellus use the formula of magnification and watch your minus sign
