A stone of weight $w$ is thrown vertically upward into the air with an initial speed $v_0$. Suppose that the air drag force $f$ dissipates an amount $fy$ of mechanical energy as the stone travels a distance $y$. What is the speed of the stone upon impact with the ground

Respuesta :

The speed of the stone upon impact with the ground [tex]{V_f}={V_o} (\frac{w-f}{w+f})^{\frac{1}{2}}[/tex]

Given

The initial speed = [tex]{V_o}[/tex]

Explanation

Acceleration

  • The state of going quickly or taking place quickly.
  • acceleration: the rate at which the speed and direction of a moving object vary over time.
  • A point or object going straight ahead is accelerated when it accelerates or decelerates.

Acceleration when ball is moving upward = (w + f)/m

[tex]$\mathrm{V}_{\mathrm{f}}^{2}-\mathrm{V}_{\mathrm{i}}^{2}=2 \overrightarrow{\mathrm{a}} \cdot \overrightarrow{\mathrm{s}}$[/tex]

[tex]$=0-\mathrm{V}_{0}^{2}=-2 \mathrm{~s}\left(\frac{\mathrm{w}+\mathrm{f}}{\mathrm{m}}\right)$[/tex]  ..... (i)

[tex]$\mathrm{s}=\frac{\mathrm{V}_{0}^{2}}{2\left[\frac{\mathrm{w}+\mathrm{f}}{\mathrm{m}}\right]}$[/tex]

While coming down

[tex]{V_i=0}[/tex]

[tex]$\mathrm{V}_{\mathrm{f}}^{2}-\mathrm{V}_{\mathrm{i}}^{2}=2 \overrightarrow{\mathrm{a}} \cdot \overrightarrow{\mathrm{s}} ; \mathrm{a}=(\mathrm{w}+\mathrm{f})$[/tex]

[tex]$\mathrm{V}_{\mathrm{f}}=\sqrt{\frac{2 \times(\mathrm{w}-\mathrm{f}) \mathrm{V}_{0}^{2}}{2(\mathrm{w}+\mathrm{f})}}$[/tex]

[tex]$\mathrm{V}_{\mathrm{f}}=\mathrm{V}_{\circ}\left(\frac{\mathrm{w}-\mathrm{f}}{\mathrm{w}+\mathrm{f}}\right)^{1 / 2}$[/tex]

The speed of the stone upon impact with the ground

[tex]$\mathrm{V}_{\mathrm{f}}=\mathrm{V}_{\circ}\left(\frac{\mathrm{w}-\mathrm{f}}{\mathrm{w}+\mathrm{f}}\right)^{1 / 2}$[/tex]

Learn more about acceleration here:

https://brainly.com/question/605631

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