Spitting cobras can defend themselves by squeezing muscles around the venom glands to squirt venom at an attacker. Supposed spitting cobra rears up to a height of 0.500 m above the ground and launches venom at 3.50 m/s, directed at 50.0° above the horizon. neglecting air is a stance, find the horizontal distance traveled by the venom before it hits the ground.

Respuesta :

Answer: 1.56 m

Explanation:

This situation is a good example of the projectile motion or parabolic motion, and the main equations that will be helpful in this situations are:

x-component:

[tex]x=V_{o}cos\theta t[/tex]   (1)

Where:

[tex]x[/tex] is the horizontal distance

[tex]V_{o}=3.5 m/s[/tex] is the initial speed

[tex]\theta=50\°[/tex] is the angle at which the venom was shot

[tex]t[/tex] is the time since the venom is shot until it hits the ground

y-component:

[tex]y=y_{o}+V_{o}sin\theta t+\frac{gt^{2}}{2}[/tex]   (2)

Where:

[tex]y_{o}=0.5m[/tex]  is the initial height of the venom

[tex]y=0[/tex]  is the final height of the venom (when it finally hits the ground)

[tex]g=-9.8m/s^{2}[/tex]  is the acceleration due gravity

Knowing this, let's begin:

First we have to find [tex]t[/tex] from (2):

[tex]0=0.5 m+3.5m/s sin(50\°) t+\frac{-9.8m/s^{2}t^{2}}{2}[/tex]   (3)

Rearranging (3):

[tex]-4.9 m/s^{2} t^{2} + 2.681 m/s t + 0.5 m=0[/tex]   (4)

This is a quadratic equation (also called equation of the second degree) of the form [tex]at^{2}+bt+c=0[/tex], which can be solved with the following formula:

[tex]t=\frac{-b \pm \sqrt{b^{2}-4ac}}{2a}[/tex] (5)

Where:

[tex]a=-4.9[/tex]

[tex]b=2.681[/tex]

[tex]c=0.5[/tex]

Substituting the known values:

[tex]t=\frac{-2.681 \pm \sqrt{(2.681)^{2}-4(-4.9)(0.5)}}{2(-4.9)}[/tex] (6)

Solving (6) we find the positive result is:

[tex]t=0.694 s[/tex] (7)

Substituting (7) in (1):

[tex]x=3.5 m/s cos(50\°) (0.694 s)[/tex]   (8)

Finally:

[tex]x=1.56 m[/tex]   (9)