3 years ago

Thế nào là gương cầu lồi

Physics

1 answer:

ale4655 [162]3 years ago

7 0

Answer:

I know I am a very good answerable teacher but I can't answer this question I don't know what

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Answer

given,

height of window = 4 m

time taken to travel = 1 s

acceleration due to gravity = 9.8 m/s²

$s = ut + \dfrac{1}{2}at^2$

$u = \dfrac{s - \dfrac{1}{2}at^2}{t}$

$u = \dfrac{4 - \dfrac{1}{2}\times 9.8\times 1^2}{1}$

u = -0.905 m/s

initial velocity of ledge v = 0

now,

v² = u² + 2 a s

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3 years ago

An object is thrown upward from the top of a 144-foot building with an initial velocity of 128 feet per second. The height h of

ankoles [38]

Answer:

After 9 seconds the object reaches ground.

Step-by-step explanation:

We equation of motion given as h = -16t²+128t+144,

We need to find in how many seconds will the object hit the ground,

That is we need to find time when h = 0

0 = -16t²+128t+144

16t²-128t-144= 0

$t=\frac{-(-128)\pm \sqrt{(-128)^2-4\times 16\times (-144)}}{2\times 16}\\\\t=\frac{128\pm \sqrt{25600}}{32}\\\\t=\frac{128\pm 160}{32}\\\\t=9s\texttt{ or }t=-1s$

Negative time is not possible, hence after 9 seconds the object reaches ground.

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The rules and expectations concerning correct or polite behavior is called _______________________.

aalyn [17]

The answer would be etiquette!

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A vibration is the primary source of a sound.

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