A golf ball is struck with a five iron on level ground. it lands 100.0 m away 4.60 s later. what was the magnitude and direction of the initial velocity? (neglect air resistance.)

Respuesta :

consider the motion in x-direction

[tex]v_{ox}[/tex] = initial velocity in x-direction = ?

X = horizontal distance traveled = 100 m

[tex]a_{x}[/tex] = acceleration along x-direction = 0 m/s²

t = time of travel = 4.60 sec

Using the equation

X = [tex]v_{ox}[/tex] t + (0.5) [tex]a_{x}[/tex] t²

100 =  [tex]v_{ox}[/tex] (4.60)

[tex]v_{ox}[/tex] = 21.7 m/s


consider the motion along y-direction

[tex]v_{oy}[/tex] = initial velocity in y-direction = ?

Y = vertical displacement  = 0 m

[tex]a_{y}[/tex] = acceleration along x-direction = - 9.8 m/s²

t = time of travel = 4.60 sec

Using the equation

Y = [tex]v_{oy}[/tex] t + (0.5) [tex]a_{y}[/tex] t²

0 = [tex]v_{oy}[/tex] (4.60) + (0.5) (- 9.8) (4.60)²

[tex]v_{oy}[/tex] = 22.54 m/s

initial velocity is given as

[tex]v_{o}[/tex] = sqrt(([tex]v_{ox}[/tex])² + ([tex]v_{oy}[/tex])²)

[tex]v_{o}[/tex] = sqrt((21.7)² + (22.54)²) = 31.3 m/s

direction: θ = tan⁻¹(22.54/21.7) = 46.12 deg