Answer:
s = 1800 m = 1.8 km
Explanation:
The distance, the speed, and the time of reach of the sound are related by the following formula:

where,
s = distance
v = speed
t = time
FOR WATER:
---------------------- eq (1)
where,
s = distance between ship and diver = ?
= speed of sound in water = 1440 m/s
t = time taken by sound in water
FOR AIR:
---------------------- eq (2)
where,
s = distance between ship and diver = ?
= speed of sound in water = 344 m/s
t + 4 s = time taken by sound in water
Comparing eq (1) and eq (2),because distance remains constant:

t = 1.25 s
Now using this value in eq (1):

<u>s = 1800 m = 1.8 km</u>
(NH4)2CO3(s) ⇄ 2NH3(g) + CO2(g) + H2O (g)
The effect that adding water (H2O) have in reaction above is that The concentration of the product would decrease, and the concentration of reactant would increase. (answer C)
<u><em>Explanation</em></u>
- If the concentration of one substance is changed, the equilibrium shift to minimize the effect of that change.
- H2O in reaction above is a product.
- Increase of water (H2O) concentration will led to the shift of equilibrium to the left ( reactant side) .The concentration of reactant increase as that of product decrease.
Answer:

Explanation:
From the exercise we know:




So, the average acceleration is:

The average force is:

Answer:
height from where rock was thrown is 27.916 m
Explanation:
speed = 7.50 m/s
θ = 30°
g= 9.8 m/s²
horizontal distance = 18 m
time require for vertical displacement

t = 2.8 sec
now for calculation of height
s = ut + 0.5 a t²
-h = v sinθ× t + 0.5 ×(-9.8)× (2.8²)
-h = 7.5 sin30°× 2.8 - 0.5 ×(9.8)× (2.8²)
-h = -27.916 m
h= 27.916 m
height from where rock was thrown is 27.916 m
Answer:
hide on a place where there is no windows take a radio
Explanation: