Respuesta :
If a projectile is projected with velocity [tex] u [/tex] at an angle [tex] \theta [/tex] with horizontal, then the horizontal and vertical components of the velocity are
[tex] u\cos \theta,u\sin \theta [/tex] respectively.
Here [tex] u=17.1\;ft/sec [/tex] and [tex] \theta=45.6^o [/tex].
The horizontal component of the initial velocity is
[tex] 17.1\cos (45.6^o)=11.96 [/tex].
The approximate value is [tex] 12.0\;ft/sec [/tex].
Correct choice is (B).