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IceJOKER [234]
3 years ago
10

The height of the Empire State Building is 318.00 meters. If a stone is dropped from the top of the building, what is the stone'

s velocity just before it strikes the ground? –1.75 meters/second –18 meters/second –79 meters/second –636 meters/second
Physics
1 answer:
jonny [76]3 years ago
7 0
D = 318 meters
vi = 0 m/s
vf =????
a = 9.81

Formula
=======
vf^2 = vi^2 + 2*a*d

Substitute and solve.
================
vf^2 = 0^2  + 2 * 9.81 * 318
vf^2 = 6239.16
v = sqrt(6239.16)
v = 78.990 m/s I guess down is minus in your classroom.
Anyway pick -79 <<<<<=======
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Answer:

w = 4,786 rad / s ,  f = 0.76176 Hz

Explanation:

For this problem let's use the concept of angular momentum

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Final after coupling

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Let's reduce the units to the SI System

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Angular velocity and frequency are related.

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Let's replace

       w = w₂ (½ M₂ R₂²) / (½ M₁ R₁² + ½ M₂ R₂²)

       w = w₂ M₂ R₂² / (M₁ R₁² + M₂ R₂²)

Let's calculate

      w = 20.94 8 0.40² / (12 0.60² + 8 0.40²)

      w = 20.94 1.28 / 5.6

      w = 4,786 rad / s

Angular velocity and frequency are related.

      w = 2π f

      f = w / 2π

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