We know that a wave is a disturbance that transfers energy through matter or space There are two main types of waves: Mechanical and Electromagnetic. Water waves are mechanical. A mechanical wave is an oscillation of matter to transfers energy, but you always need a medium (substance such as: solid, liquid, gas, plasma) to transport it. The medium for water waves is, in fact, the water. For example, ripple in water is a surface wave. On the other hand, electromagnetic waves don't need a medium to transport, they can do it through the empty space. Then, this is the major characteristic that makes these two types of waves different.
Answer: 2940 J
Explanation: solution attached:
PE= mgh
Substitute the values:
PE= 10kg x 9.8 m/s² x 30 m
= 2940 J
Psychoanalytic dream interpretation is a subdivision of dream interpretation as well as a subdivision of psychoanalysis pioneered by Sigmund Freud in the early twentieth century. Psychoanalytic dream interpretation is the process of explaining the meaning of the way the unconscious thoughts and emotions are processed in the mind during sleep.
There have been multiple methods used in psychoanalytic dream interpretation, including Freud's method of dream interpretation, the symbolic method, and the decoding method. The Freudian method is the most prominently used in psychoanalysis and has been for the last century. Psychoanalytic dream interpretation is used mainly for therapeutic purposes in a variety of settings. Although these theories are used, none have been solidly proven and much has been left open to debate among researchers. Some studies have shown that areas of dream interpretation can be invalid and therefore a decline in importance has been seen in psychoanalytic dream interpretation.

When something is heated or cooled, its length changes by an amount proportional to the original length and the change in temperature: linear expansion : ΔL=αL0ΔT (α is the coefficient of linear expansion) The coefficient of linear expansion depends only on the material an object is made from.
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