Question

A projectile is fired with an initial speed of 1000 m/s at an angle of 37 degrees above the horizontal. If air resistance is neglected, the horizontal component of the projectile's velocity after 20 s is approximately

A) 600 m/s
B) 800 m/s
C) 640 m/s
D) 40 m/s
E) 160 m/s

please help to solve this problem! thanks

Answer 1

Vf = Vo + g*t.

Vf = 1000 * cos37 + 9.8 * 20,
Vf = 798.6 + (-196) = 602.6 m / s.

Answer 2

CORRECTION:

Vf = 1000 + (-9.8) * 20 = 1000 -196 = 804 @ 37 deg.

Vf(hor) = 804cos37 = 642 m /s.