contestada

A dog leaps horizontally off a 70 m cliff with a speed of 6 m/s, how far from the base will the dog land?

Respuesta :

Answer:

[tex]\Delta x=22.67786838m[/tex]

Explanation:

Let's use projectile motion equations. First of all we need to find the travel time. So we are going to use the next equation:

[tex]y-y_0=v_o*sin(\theta)*t-\frac{1}{2}*t^2[/tex] (1)

Where:

[tex]y=Final\hspace{3}position\hspace{3}at\hspace{3}y-axis[/tex]

[tex]y_o=Initial\hspace{3}position\hspace{3}at\hspace{3}y-axis[/tex]

[tex]v_o=initial\hspace{3}velocity[/tex]

[tex]t=travel\hspace{3}time[/tex]

[tex]g=gravity\hspace{3}constant[/tex]

[tex]\theta=Initial\hspace{3}launch\hspace{3}angle[/tex]

In this case:

[tex]\theta=0[/tex]

Because the dog jumps horizontally

Let's asume the gravity constant as:

[tex]g=9.8[/tex]

[tex]y=0[/tex]

Because when the dog reach the base the height is 0

[tex]y_o=70[/tex]

[tex]v_o=6[/tex]

Now let's replace the data in (1)

[tex]y_o-\frac{1}{2} *(9.8)*t^2+70[/tex]

Isolating t:

[tex]t=\pm\sqrt{\frac{2*70}{9.8} } =3.77964473[/tex]

Finally let's find the horizontal displacement using this equation:

[tex]\Delta x=v_o*cos(\theta)*t[/tex]

Replacing the data:

[tex]\Delta x=6*1*3.77964473=22.67786838m[/tex]