Answer:
The reflection of sound waves
Explanation:
An echo is a reflection of sound that bounces of of one thing to another.
The type of reaction that occurs without the addition of heat is called spontaneous reaction. That is option D.
<h3>What is spontaneous reaction?</h3>
Spontaneous reaction is defined as the reaction where by new substances are formed naturally without the addition of extra energy in the form of heat.
Therefore, the type of reaction that occurs without the addition of heat is called spontaneous reaction
Learn more about heat here:
brainly.com/question/13439286
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Answer: The derivative of a constant term is always 0. So the acceleration of the body would be zero. Hence, the acceleration of a body moving with uniform velocity will always be zero.
Hope this helps :) :)
