Answer:
45 s
Explanation:
To find the time it takes to stop, we first find the deceleration, a of the car from
v² = u² + 2as and a = (v² - u²)/2s were v = final velocity of car = 0 mph = 0 m/s, u = initial velocity of car = 30 mph = 30 × 1609.34 ft ÷ 3600 s = 13.41 ft/s and s = distance = 300 ft. Substituting the values into a, we ave
a = (v² - u²)/2s = (0² - 13.41²)/2×300 = -0.3 ft/s²
We then find the time for this deceleration from v = u + at ⇒ t = (v - u)/a
t = (v - u)/a = (0 - 13.41 ft/s)/-0.3 ft/s² = - 13.41 ft/s/-0.3 ft/s² = 44.7 s ≅ 45 s
So it takes 45 seconds to stop.
![v = \frac{ \:the covered distance}{time} \\](https://tex.z-dn.net/?f=v%20%3D%20%20%5Cfrac%7B%20%5C%3Athe%20covered%20distance%7D%7Btime%7D%20%5C%5C%20%20)
![v = \frac{600}{25} = \frac{6 \times 100}{25} = 6 \times 4 = 24 \: \\](https://tex.z-dn.net/?f=v%20%3D%20%20%5Cfrac%7B600%7D%7B25%7D%20%3D%20%20%5Cfrac%7B6%20%5Ctimes%20100%7D%7B25%7D%20%3D%206%20%5Ctimes%204%20%3D%2024%20%5C%3A%20%20%5C%5C%20%20%20)
![v = 24 \: \frac{m}{s} \\](https://tex.z-dn.net/?f=v%20%3D%2024%20%5C%3A%20%20%5Cfrac%7Bm%7D%7Bs%7D%20%5C%5C%20%20)
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If west means the west of the axis x the velocity equal :
![- 24 \: \frac{m}{s} \\](https://tex.z-dn.net/?f=%20-%2024%20%5C%3A%20%20%5Cfrac%7Bm%7D%7Bs%7D%20%5C%5C%20%20)
Explanation:
1.The light reflected from the CD/DVD or soap bubble or oil film forms an interference with the surrounding light. The inference both constructive and destructive making some color appear and some disappear.
2.As light behaves as wave it will interfere differently at different angles. At certain angle it will interfere constructively and at certain angle it will interfere destructively making some color brighter and some disappear. So, at different angles the color are different.