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A water balloon is observed to emerge from an open window of a gymnasium. The window is 9.5 m above the ground. Through miracles of technology (involving doppler radar and automated video analysis), it is determined that the balloon leaves the window with a speed of 12.5 m/s at an angle of 45∘
45

relative to horizontal.
(A) How much time elapses from when the balloon is passing through the window to when it hits the ground? s
(B) How far from the wall does the balloon hit the ground? m

It is determined that someone within the gymnasium threw the balloon from the floor level of the gymnasium,which is level with the ground outside.
(C) Assuming the launch point is from the floor level, how far from the wall was the balloon launched? m

Respuesta :

A) The balloon hits the ground after t = 2.55 sec

B) Horizontal distance covered: 22.5 m

C) Horizontal distance covered: 15.9 m

Explanation:

A)

The motion of the balloon is a projectile motion, so it consists of a uniformly accelerated motion along the vertical direction and of a uniform motion along the horizontal direction.

The vertical motion can be analyzed using the suvat equation:

[tex]s=u_y t - \frac{1}{2}gt^2[/tex]

where:

s = -9.5 m is the vertical displacement of the balloon when it reaches the ground

[tex]u_y = u sin \theta[/tex] is the initial vertical velocity of the balloon, where

u = 12.5 m/s is the initial speed

[tex]\theta=45^{\circ}[/tex] is the angle of projection

[tex]g=9.8 m/s^2[/tex] is the acceleration of gravity

t is the time of flight

Re-arranging and solving for t,

[tex]-9.5 = (12.5)(sin 45^{\circ}) t -\frac{1}{2}(9.8)t^2\\-9.5 = 8.8 t - 4.9 t^2\\4.9t^2-8.8t-9.5=0[/tex]

And solving for t,

t = -0.76 s

t = 2.55 s

We discard the first negative solution, so the balloon reaches the ground after 2.55 seconds.

B)

In order to find the horizontal distance covered by the balloon, we use the equation of the horizontal motion:

[tex]x=u_x t[/tex]

where:

[tex]u_x = u cos \theta[/tex] is the initial horizontal velocity, where

u = 12.5 m/s is the initial speed

[tex]\theta=45^{\circ}[/tex] is the angle of projection

t is the time

By substituting

t = 2.55 s (time of flight)

we find the horizontal distance covered by the balloon during this time:

[tex]x=(u cos \theta) t = (12.5)(cos 45^{\circ})(2.55)=22.5 m[/tex]

C)

In this case, the equation for the vertical motion would have been:

[tex]s=u_y t - \frac{1}{2}gt^2[/tex]

But this time,

s = 0

Because the vertical displacement is zero.

Therefore, the solution of the equation for t would be:

[tex]u_yt-\frac{1}{2}gt^2=0\\u_y - \frac{1}{2}gt=0\\t=\frac{2u_y}{g}=\frac{2(12.5)(sin 45^{\circ})}{9.8}=1.80 s[/tex]

And so, the horizontal distance covered by the balloon in this second case would be:

[tex]x=u_x t = (12.5)(cos 45^{\circ})(1.80)=15.9 m[/tex]

Learn more about projectile motion:

brainly.com/question/8751410

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