A basketball player shoots the ball with an initial velocity of 17.1 ft/sec. at an angle of 45.6° with the horizontal. To the nearest tenth, find the initial horizontal component of the vector that represents the velocity of the ball.

A. 5.1 ft/sec.
B. 12.0 ft/sec.
C. 12.2 ft/sec.
D. 17.5 ft/sec.

Respuesta :

The answer is B. 12.0 ft/sec

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).