Answer:
THE DISTANCE OF THE ROCK REFLECTING HER VOICE IS 82.5 METERS.
Explanation:
In sound waves, the speed of a sound is equal to twice the distance divided by time.
Mathematically,
Speed = 2 * Distance/ Time
Speed = 33- m/s
Time = 0.5 second
Distance = unknown
So re-arranging and introducing the variables into the formula, we have;
Distance = speed * time / 2
Distance = 330 * 0.5 / 2
Distance = 82.5 meters.
The distance away from the rock face which is reflecting her voice is 82.5 meters.
(I think you have a mistake in your question as the addition is 30mL, not 100mL)
when PH = - ㏒[H+]
and here we have HClO4 is the strong acid
So PH = - ㏒[HClO4]
moles of HClO4 = 0.1 L *0.18 m = 0.018 M
moles of LiOH = 0.03 L * 0.27 m = 0.0081 M
when the total volume = 0.1L + 0.03L = 0.13 L
∴ [HClO4] = (0.018-0.0081)/0.13 L
= 0.076 M
PH = -㏒ 0.076
= 1.12
Potassium chloride reacts with ammonium nitrate to give ammonium chloride and potassium nitrate.
This is a type of double displacement reaction. The balanced chemical equation can be represented as,

Total ionic equation for this reaction will be,

There is no apparent reaction as this reaction is not accompanied by the formation of a gas or a solid precipitate. We cannot observe any visual reaction as there is not net reaction taking place. All the ions remain as spectator ions.
My Plate was released to replace the food pyramid and displays the five main food groups. The plate visually shows approximate proportions of the different food groups as opposed tot the food pyramid.