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kow [346]
3 years ago
9

You throw a small rock straight up from the edge of a highway bridge that crosses a river. the rock passes you on its way down,

8.00 s after it was thrown. what is the speed of the rock just before it reaches the water 21.0 m below the point where the rock left your hand? ignore air resistance
Physics
1 answer:
maw [93]3 years ago
4 0
V^2=u^2 +2aS
U is found first by considering that first 8 secs and using v=u+at. {different v and u though}

V=-u+gt.
Magnitude of u = magnitude of v if there is no resistance ( because the conservation of energy says the k. E. must be the same when it passes you as when it left your hand).... up is negative here, down is positive.
V+v=gt
2v= g x 8
V=4xg.= the initial velocity for the next calculation
V^2=(4g)^2+(2xgx21)

So v can be calculated.

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Answer:

<h2>4.9N approx.</h2>

Explanation:

Step one:

given data

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Required

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Step two:

<em>"By definition, Torque is the twisting force that tends to cause rotation. </em>

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Mathematically,

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r = radius

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3 years ago
A differnece in electric potential is required for an electric charge to flow through a wire.
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Explanation:

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Uma carga puntiforme de + 3,0uC é colocada em um ponto P de um campo elétrico gerado por uma partícula eletrizada com carga desc
expeople1 [14]

Responda:

1) E = 6 × 10 ^ 6NC ^ -1 2) Q = 6 × 10 ^ -5

Explicação:

Dado o seguinte:

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1)

Lembre-se:

Força elétrica (Fe) = carga (q) * Intensidade do campo elétrico (E)

Fe = qE; E = Fe / q

E = 18N / (3 × 10 ^ -6C)

E = 6N / 10 ^ -6C

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2)

Lembre-se:

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E = intensidade do campo elétrico

Q = carga de origem

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6 × 10 ^ 6 = (9,0 × 10 ^ 9 * Q) / 0,3 ^ 2

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Q = 6 × 10 ^ -5 = 60 × 10 ^ -6 = 60μC

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Answer:

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