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charle [14.2K]
2 years ago
9

A ball is thrown vertically upward, which is the positive direction. a little later it returns to its point of release. the ball

is in the air for a total time of 8.00 s. what is its initial velocity? neglect air resistance.
Physics
1 answer:
Lady_Fox [76]2 years ago
7 0
<span>Final Velocity = Vf = 0 m/s --------------> (Vf = 0 because ball's speed at its max height is 0) Initial Velocity = Vi = ? Total time (upward & downward) = 8.0 seconds * Time upward = 4 seconds & ................( As time for ball upward & downward is equal ) * Time downward = 4 seconds.. Gravitational Acceleration = g = -9.8 m/s² Use Equation; Vf = Vi - gt 0 = Vi - 9.8 * 4 0 = Vi - 39.2 39.2 = Vi => Vi = Initial Velocity = 39.2 m/s</span>
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Answer:

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(D) The final volume of the helium is 0.066 cubic meter

Explanation:

(B) ∆U = P(V2 - V1)

From ideal gas equation, PV = nRT

T1 = 21°C = 294K, V1 = 0.033m^3, n = 2moles, V2 = 2× 0.033=0.066m^3

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Assuming a closed system

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(C) Final volume = 2×initial volume = 2×0.033= 0.066 cubic meter

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A radio telescope helped the astronomers discover the CMB.

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