A wave is a disturbance that moves along a medium from one end to the other. If one watches an ocean wave moving along the medium (the ocean water), one can observe that the crest of the wave is moving from one location to another over a given interval of time. The crest is observed to cover distance. The speed of an object refers to how fast an object is moving and is usually expressed as the distance traveled per time of travel. In the case of a wave, the speed is the distance traveled by a given point on the wave (such as a crest) in a given interval of time. In equation form,
Answer:
t = 1.75
t = 0.04
Explanation:
a)
For part 1 we want to use a kenamatic equation with constant acceleration:
X = 1/2*a*t^2
isolate time
t = sqrt(2X / a)
Plugin known variables. Acceleration is the force of gravity which is 9.8 m/s^2
t = sqrt(2*15m / 9.8m/s^2)
t = 1.75 s
b)
The speed of sound travels at a constant speed therefore we don't need acceleration and can use the equation:
v = d / t
isolate time
t = d / v
plug in known variables
t = 15m / 340m/s
t = 0.04 s
Let t=time to reach the ground=8 secs, g= acceleration of gravity. The speed v on reaching the ground is gt=8g=78.4 m/s where g=9.8 m/s/s approx.
Choice C.
That's when convection stops.
