At what height h above the ground does the projectile have a speed of 0.5v?
Express your answer in terms of v and the magnitude of the acceleration of gravity g.

Respuesta :

Answer:

[tex]h=\dfrac{3v^2}{8g}[/tex]

Explanation:

It is given that,

Speed of the projectile is 0.5 v. Let h is the height above the ground. Using the first equation of motion to find it.

[tex]v=u+at[/tex]

[tex]v=u-gt[/tex]

Initial speed of the projectile is v and final speed is 0.5 v.

[tex]0.5v=v-gt[/tex]

[tex]t=\dfrac{v}{2g}[/tex]

g is the acceleration due to gravity

Let h is the height above the ground. Using the second equation of motion as :

[tex]h=vt-\dfrac{1}{2}gt^2[/tex]

[tex]h=v\dfrac{v}{2g}-\dfrac{1}{2}g(\dfrac{v}{2g})^2[/tex]

[tex]h=\dfrac{3v^2}{8g}[/tex]

So, the height of the projectile above the ground is [tex]\dfrac{3v^2}{8g}[/tex]. Hence, this is the required solution.