A toy rocket is launched with an initial ve- locity of 12.0 m>s in the horizontal direction from the roof of a 30.0-m-tall building. The rocket’s engine produces a horizontal acceleration of 11.60 m>s 3 2t, in the same direction as the initial velocity, but in the vertical direction the acceleration is g, down- ward. Ignore air resistance. What horizontal distance does the rocket travel before reaching the ground?

Respuesta :

Answer:

D=90.3m.

Explanation:

Here we got a parabolic motion problem, On the Y axis we have a free-fall motion, so the time to reach the ground is given by:

[tex]y=yo+Vo*t+\frac{1}{2}*a*t^2\\0=30m+0*t-\frac{1}{2}*(-9.8)*t^2\\t=2.5s[/tex]

Having that time we now can calculate the horizontal distance traveled by the rocket.

The acceleration is a continous function, if we integrate the acceleration we obtain the velocity:

[tex]vf=\int\limits^{t}_0 {11.60*2t} \, dt\\ vf=11.6m/s^3*t^2[/tex]

[tex]Vx(t)=12.0m/s+11.6m/s^3*t^2[/tex]

the displacement is given by:

[tex]D=\int\limits^t_0 {Vx} \, dx[/tex]

[tex]D=12.0m/s*t+3.86m/s^3*t^3\\[/tex]

Substituting the time:

D=90.3 m