Answer:
4v/3
Explanation:
Assume elastic collision by the law of momentum conservation:
![m_1v = m_1v_1 + m_2v_2](https://tex.z-dn.net/?f=m_1v%20%3D%20m_1v_1%20%2B%20m_2v_2)
where v is the original speed of car 1, v1 is the final speed of car 1 and v2 is final speed of car 2. m1 and m2 are masses of car 1 and car 2, respectively
Substitute ![m_2 = m_1/2 \& v_1 = v/3](https://tex.z-dn.net/?f=m_2%20%3D%20m_1%2F2%20%5C%26%20v_1%20%3D%20v%2F3)
![m_1v = \frac{m_1v}{3} + \frac{m_1v_2}{2}](https://tex.z-dn.net/?f=m_1v%20%3D%20%5Cfrac%7Bm_1v%7D%7B3%7D%20%2B%20%5Cfrac%7Bm_1v_2%7D%7B2%7D)
Divide both side by
, then multiply by 6 we have
![6v = 2v + 3v_2](https://tex.z-dn.net/?f=6v%20%3D%202v%20%2B%203v_2)
![3v_2 = 4v](https://tex.z-dn.net/?f=3v_2%20%3D%204v)
![v_2 = \frac{4v}{3}](https://tex.z-dn.net/?f=v_2%20%3D%20%5Cfrac%7B4v%7D%7B3%7D)
So the final speed of the second car is 4/3 of the first car original speed
I would say letter A to this because we need rain water for crops plants. Also we need it so that we can drink it. Its less great over sea because as it merge with the salt in the ocean it becomes less drinkable and less usable.
Answer: 0.790 g/cm3
Explanation:
The density of acetone is 790 Kg/m3.
To convert from Kg to g we multiply by 1000 (1 Kg = 1000 g)
To convert from m3 to cm3 we multiply by 10∧6
So, The density of acetone in (g/cm3) = (790 x 1000) / (10∧6) = 0.79 g/cm3
Answer: 1.176×10^-3 s
Explanation: The time constant formulae for an RC circuit is given below as
t =RC
Where t = time constant , R = magnitude of resistance = 21 ohms , C = capacitance of capacitor = 56 uf = 56×10^-6 F
t = 56×10^-6 × 21
t = 1176×10^-6
t = 1.176×10^-3 s