A projectile is fired from the origin of the coordinate system with an initial velocity v0 in a direction making an angle α with the horizontal. Calculate the time required for the projectile to cross a line passing through the origin and making an angle β < α with the horizontal.

Respuesta :

Answer:

Explanation:

Given

launching inclination is [tex]\alpha[/tex]

suppose u is the initial velocity

vertical velocity [tex]v_y=u\sin \alpha[/tex]

horizontal velocity [tex]v_x=u\cos \alpha[/tex]

Vertical distance traveled by Projectile is

[tex]y=v_y\times t-\frac{1}{2}gt^2----1[/tex]

Now equation of line passing through origin

[tex]y=x\tan \beta------2[/tex]

Equating two equation we get

[tex]x\tan \beta=v_y\times t-\frac{1}{2}gt^2[/tex]

putting [tex]x=v_x\times t=u\cos \alpha \times t[/tex]

[tex]u\cos \alpha \tan \beta \cdot t=v_y\times t-\frac{1}{2}gt^2[/tex]

[tex]t\left [ u\sin \alpha -u\cos \alpha \tan\beta -\frac{gt}{2}\right ]=0[/tex]

[tex]t=\frac{2u\left [ \sin \alpha -\cos \alpha \tan \beta \right ]}{g}[/tex]