The answer is D. As the ambulance gets closer, the sound waves are compressed relative to the person; so the frequency increases.
Answer:It is an Endothermic reaction
Explanation:
Exothermic reaction
An exothermic reaction is one that releases energy in the form of heat or light.
Endothermic reaction
An endothermic reaction is one that absorbs energy in the form of heat or light.
Answer:
When the same amount of heat is added to cold sand and cold water, the temperature change of sand will be higher because of its lower specific heat capacity.
What is specific heat capacity?
Specific heat capacity is the quantity
of heat required to raise a unit mass of
a substance by 1 kelvin.
Specific heat capacity of water and sand
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Δθ = Q/mc
Thus, for an equal mass of water and sand, when the same amount of heat is added to cold sand and cold water, the temperature change of sand will be higher because of its lower specific heat capacity.
Answer:
It decreases
Explanation:
The air pressure tends to be higher on the places with the lowest altitudes, and lower at the places with higher altitudes. Basically, the air pressure is the wight of the air, and since the air is denser and heavier at the lower altitudes, the air pressure is higher, while on the higher altitudes the air is less dense, thus the air pressure is lower. So in practice we can expect that the air pressure in a low valley will be higher than the air pressure at the top of higher mountain.