Suppose a football is kicked with an initial velocity of 82 ft/sec., at an angle of

58° to the ground. What is the position of the ball after two seconds?

(Remember: Acceleration due to gravity is 32 ft/s².) Round your answer

to the nearest whole foot. Show all work.

Respuesta :

Answer:

The position P is:

[tex]P = 87\^x + 75\^y[/tex] ft     Remember that the position is a vector. Observe the attached image

Step-by-step explanation:

The equation that describes the height as a function of time of an object that moves in a parabolic trajectory with an initial velocity [tex]s_0[/tex] is:

[tex]y(t) = y_0 + s_0t -16t ^ 2[/tex]

Where [tex]y_0[/tex] is the initial height = 0 for this case

We know that the initial velocity is:

82 ft/sec at an angle of 58 ° with respect to the ground.

So:

[tex]s_0 = 82sin(58\°)[/tex] ft/sec

[tex]s_0 = 69.54[/tex] ft/sec

Thus

[tex]y(t) = 69.54t -16t ^ 2[/tex]

The height after 2 sec is:

[tex]y(2) = 69.54 (2) -16 (2) ^ 2[/tex]

[tex]y(2) = 75\ ft[/tex]

Then the equation that describes the horizontal position of the ball is

[tex]X(t) = X_0 + s_0t[/tex]

Where

[tex]X_ 0 = 0[/tex] for this case

[tex]s_0 = 82cos(58\°)[/tex] ft / sec

[tex]s_0 = 43.45[/tex] ft/sec

So

[tex]X(t) = 43.45t[/tex]

After 2 seconds the horizontal distance reached by the ball is:

[tex]X (2) = 43.45(2)\\\\X (2) = 87\ ft[/tex]

Finally the vector position P is:

[tex]P = 87\^x + 75\^y[/tex] ft

Ver imagen luisejr77