Answer:
![T_f=57.21\ ^{\circ}C](https://tex.z-dn.net/?f=T_f%3D57.21%5C%20%5E%7B%5Ccirc%7DC)
Explanation:
Given:
- mass of aluminium,
![m_a=0.2\ kg](https://tex.z-dn.net/?f=m_a%3D0.2%5C%20kg)
- initial temperature of the aluminium cylinder,
![T_{ia}=-20\ ^{\circ}C](https://tex.z-dn.net/?f=T_%7Bia%7D%3D-20%5C%20%5E%7B%5Ccirc%7DC)
- mass of coffee,
![m_c=0.5\ kg](https://tex.z-dn.net/?f=m_c%3D0.5%5C%20kg)
- initial temperature of coffee,
![T_{ic}=85\ ^{\circ}C](https://tex.z-dn.net/?f=T_%7Bic%7D%3D85%5C%20%5E%7B%5Ccirc%7DC)
- specific heat of coffee (assuming water),
![c_w=1000\ J.kg^{-1}.^{\circ}C^{-1}](https://tex.z-dn.net/?f=c_w%3D1000%5C%20J.kg%5E%7B-1%7D.%5E%7B%5Ccirc%7DC%5E%7B-1%7D)
- specific heat of aluminium,
![c_a=900\ J.kg^{-1}.^{\circ}C^{-1}](https://tex.z-dn.net/?f=c_a%3D900%5C%20J.kg%5E%7B-1%7D.%5E%7B%5Ccirc%7DC%5E%7B-1%7D)
When the coffee and the aluminium cylinder come in contact then heat released by the coffee is equal to the heat gained by the aluminium.
<u>Mathematically:</u>
![Q_c=Q_a](https://tex.z-dn.net/?f=Q_c%3DQ_a)
![m_c.c_w. (T_{ic}-T_f)=m_a.c_a.(T_f-T_{ia})](https://tex.z-dn.net/?f=m_c.c_w.%20%28T_%7Bic%7D-T_f%29%3Dm_a.c_a.%28T_f-T_%7Bia%7D%29)
![0.5\times 1000\times (85-T_f)=0.2\times 900\times (T_f-(-20))](https://tex.z-dn.net/?f=0.5%5Ctimes%201000%5Ctimes%20%2885-T_f%29%3D0.2%5Ctimes%20900%5Ctimes%20%28T_f-%28-20%29%29)
![42500-500\times T_f=180\times T_f+3600](https://tex.z-dn.net/?f=42500-500%5Ctimes%20T_f%3D180%5Ctimes%20T_f%2B3600)
is the final temperature of agreement.
They mostly affect it negatively. Often times, urban populations can overcrowd, overuse or pollute a water supply. Take the river Thames for example, in London. It's used so much that its waters are hardly safe to swim in, much less drink. Also, we cram water in reservoirs, making it safe for us, but keeping local wildlife from it.
Have a great night/day!
-Dylan (AKA Animus
Answer:
B
Overgrazing and poor farming techniques can also lead to soil erosion, but it is important to remember that not all causes are human; climate and natural soil quality are also important factors to consider in tropical and mountainous regions.
Explanation:
Be would be the correct answer because Choice D sounds like another fact or another sentence in a passage. It doesn't sound like a sentence to explain or support the passage. Also Choice A sounds like that too.
Choice C could sound like it too though because when they have details that could really help and support it.
Your welcome pls. tell me if im wrong.
<u><em>my instagram is = itsstephbored</em></u>
Answer:
1933 Hz
1956 Hz
Explanation:
= Velocity of object
= Velocity of source
v = Velocity of sound
From Doppler effect
![f=f'\dfrac{v+v_0}{v-v_s}\\\Rightarrow f=1910\dfrac{1522+14}{1522-4}\\\Rightarrow f=1932.64822134\ Hz=1933\ Hz](https://tex.z-dn.net/?f=f%3Df%27%5Cdfrac%7Bv%2Bv_0%7D%7Bv-v_s%7D%5C%5C%5CRightarrow%20f%3D1910%5Cdfrac%7B1522%2B14%7D%7B1522-4%7D%5C%5C%5CRightarrow%20f%3D1932.64822134%5C%20Hz%3D1933%5C%20Hz)
The frequency of the sound detected by subB is 1933 Hz
![f=f'\dfrac{v+v_0}{v-v_s}\\\Rightarrow f=1932.64822134\dfrac{1522+4}{1522-14}\\\Rightarrow f=1955.7169\ Hz=1956\ Hz](https://tex.z-dn.net/?f=f%3Df%27%5Cdfrac%7Bv%2Bv_0%7D%7Bv-v_s%7D%5C%5C%5CRightarrow%20f%3D1932.64822134%5Cdfrac%7B1522%2B4%7D%7B1522-14%7D%5C%5C%5CRightarrow%20f%3D1955.7169%5C%20Hz%3D1956%5C%20Hz)
The frequency of the sound detected by subA is 1956 Hz