From the edge of a cliff, a 0.46 kg projectile is launched with an initial kinetic energy of 1430 J. The projectile's maximum upward displacement from the launch point is +150 m. What are the (a) horizontal and (b) vertical components of its launch velocity? (c) At the instant the vertical component of its velocity is 65 m/s, what is its vertical displacement from the launch point? Take up to be the positive direction.

Respuesta :

Answer:

Explanation:

Given

mass of Projectile(m)=0.46 kg

Initial Kinetic Energy=1430 J

Maximum upward displacement from Launch point=150 m

[tex]K.E.=\frac{mv^2}{2}[/tex]

[tex]1430\times 2=0.46\times v^2[/tex]

v=78.85 m/s

and [tex]H_{max}=\frac{v^2\sin ^2\theta }{2g}[/tex]

[tex]150=\frac{(78.85)^2\sin ^2\theta }{2\times 9.8}[/tex]

[tex]\sin \theta =0.687[/tex]

[tex]\theta =43.39^{\circ}[/tex]

initial horizontal velocity[tex](v_x)=v\cos \theta [/tex]

[tex]v_x=78.84\times \cos (43.39)=57.29 m/s[/tex]

Initial vertical velocity[tex](v_y)=v\sin \theta [/tex]

[tex]v_y=78.85\times \sin (43.39)[/tex]

[tex]v_y=54.16 m/s[/tex]

(c)vertical velocity at any instant=65 m/s

Since initial vertical velocity is 54.16 m/s

so 65 m/s will be acquired when projectile started falling below cliff

[tex]v^2-u^2=2 a s[/tex]

[tex]65^2-54.16^2=2\times 9.8\times s[/tex]

[tex]s=65.90 m[/tex]