Answer:
<em>a</em><em>.</em><em> </em><em>w</em><em>e</em><em>a</em><em>t</em><em>h</em><em>e</em><em>r</em><em>i</em><em>n</em><em>g</em><em>.</em>
Explanation:
<em>w</em><em>e</em><em>a</em><em>t</em><em>h</em><em>e</em><em>r</em><em>i</em><em>n</em><em>g</em><em> </em><em>i</em><em>s</em><em> </em><em>t</em><em>h</em><em>e</em><em> </em><em>p</em><em>r</em><em>o</em><em>c</em><em>e</em><em>s</em><em>s</em><em> </em><em>o</em><em>f</em><em> </em><em>b</em><em>r</em><em>e</em><em>a</em><em>k</em><em>i</em><em>n</em><em>g</em><em> </em><em>d</em><em>o</em><em>w</em><em>n</em><em> </em><em>r</em><em>o</em><em>c</em><em>k</em><em>s</em><em> </em><em>a</em><em>n</em><em>d</em><em> </em><em>m</em><em>i</em><em>n</em><em>e</em><em>r</em><em>a</em><em>l</em><em>s</em><em> </em><em>i</em><em>n</em><em>t</em><em>o</em><em> </em><em>s</em><em>m</em><em>a</em><em>l</em><em>l</em><em>e</em><em>r</em><em> </em><em>p</em><em>i</em><em>e</em><em>c</em><em>e</em><em>s</em><em> </em><em>b</em><em>y</em><em> </em><em>w</em><em>a</em><em>t</em><em>e</em><em>r</em><em>,</em><em> </em><em>w</em><em>i</em><em>n</em><em>d</em><em>,</em><em> </em><em>a</em><em>n</em><em>d</em><em> </em><em>i</em><em>c</em><em>e</em><em>.</em>
Refraction is the change in direction of a wave, caused by the change in the wave's speed. Examples of waves include sound waves and light waves. Refraction is seen most often when a wave passes from one transparent medium to another transparent medium. Different types of medium include air and water. When a wave passes from one transparent medium to another transparent medium, the wave will change its speed and its direction. For example, when a light wave travels through air and then passes into water, the wave will slow and change direction.
An opera singer breaks a thin glass with only the use of her high frequency voice
The initial height of the first body is given by:

where
g is the gravitational acceleration
t is the time it takes for the body to reach the ground
Substituting t=1 s, we find

The second body takes takes t=2 s to reach the ground, so it was located at an initial height of

The second body started its fall 1 second before the first body, therefore when the second body started its fall, the first body was located at its initial height, i.e. at 4.9 m from the ground.
Answer:

Explanation:
A body has acceleration when there is a change in the velocity vector, either in magnitude or direction. In this case we only have a change in magnitude. The average acceleration represents the speed variation that takes place in a given time interval.
a)

b)
