contestada

A rock is projected upward from the surface of the moon, at time t = 0.0 s, w a velocity of 30 m/s. The acceleration due to gravity at the surface of the moon in 1.62 m/s2. What is the maximum height of the rock above the surface?

Respuesta :

Answer: 277.777 m

Explanation:

The situation described here is parabolic movement. However, as we are told that the rock was projected upward from the surface, we will only use the equations related to the Y axis.

In this sense, the movement equations in the Y axis are:

[tex]y-y_{o}=V_{o}.t+\frac{1}{2}g.t^{2}[/tex]    (1)

[tex]V=V_{o}-g.t[/tex]    (2)

Where:

[tex]y[/tex]  is the rock's final position

[tex]y_{o}=0[/tex]  is the rock's initial position

[tex]V_{o}=30\frac{m}{s}[/tex] is the rock's initial velocity

[tex]V[/tex] is the final velocity

[tex]t[/tex] is the time the parabolic movement lasts

[tex]g=1.62\frac{m}{s^{2}}[/tex]  is the acceleration due to gravity at the surface of the moon

As we know [tex]y_{o}=0[/tex] , equation (2) is rewritten as:

[tex]y=V_{o}.t+\frac{1}{2}g.t^{2}[/tex]    (3)

On the other hand, the maximum height  is accomplished when [tex]V=0[/tex]:

[tex]V=V_{o}-g.t=0[/tex]    (4)

[tex]V_{o}-g.t=0[/tex]    

[tex]V_{o}=g.t[/tex]    (5)

Finding [tex]t[/tex]:

[tex]t=\frac{V_{o}}{g}[/tex]    (6)

Substituting (6) in (3):

[tex]y=V_{o}(\frac{V_{o}}{g})+\frac{1}{2}g(\frac{V_{o}}{g})^{2}[/tex]    (7)

[tex]y_{max}=\frac{{V_{o}}^{2}}{2g}[/tex]    (8)  Now we can calculate the maximum height of the rock

[tex]y_{max}=\frac{{(30m/s)}^{2}}{(2)(1.62m/s^{2})}[/tex]   (9)

Finally:

[tex]y_{max}=277.777m[/tex]