I am doing some review with a friend and I am having trouble with a few problems. I think I am making an incorrect assumption somewhere since all of the problems I am having trouble with are similar.(adsbygoogle = window.adsbygoogle || []).push({});

Problem:

A projectile is shot from the edge of a cliff h=205meters above the ground with an initial speed of [tex]v_0=155[/tex]m/s at an angl of 37 degrees with the horizontal.

Equations: [tex]v = v_0 + a t[/tex] [tex]x = x_0 + v_0 t + (1/2) a t^2[/tex] [tex]v^2 = v_0^2 + 2 a \Delta x[/tex] in both x and y directions.

From this I have written that:

[tex]x_0=0[/tex]

[tex]x_f=?[/tex]

[tex]y_0=205[/tex]

[tex]y_f=0[/tex]

[tex](v_o)_x=155cos37[/tex]

[tex](v_0)_y=155sin37[/tex]

(a) Determine the time taken by the projectile to hit a point P atground levelShould it just be [tex]y = (v_0)_y t + (1/2) (-g) t^2[/tex]?

Which gives me a quadratic???

[tex]-205=(155sin37)^2t-4.9t^2=21.03s[/tex]

(b) Determine the Range of the projectile as neasured from thebaseof the cliff.

(c) At the instant before the projectile hits point P, find the vertical and horizontal components of its velocity (take up and to the right as positive).

(d) Magnitude and direction of velocity (angle made with the horizontal in degrees below the horizontal):

(e) The MAX height above the cliff top thatthe projectile reached:

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# Homework Help: Projectile Motion 1

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