Projectile Motion at an Angle: Calculating Time and Distance

[MozAngeles]

Homework Statement

When the dried-up seed pod of a scotch broom plant bursts open, it shoots out a seed with an initial velocity of 2.64 m/s at an angle of 30.0˚ below the horizontal. The seed pod is 0.465 m above the ground.
How long does it take for the seed to land?
What horizontal distance does it cover during its flight?

Homework Equations

Voy=Vsin$$\theta$$
Vox=Vcos$$\theta$$
h = y0 + v0*t + 1/2 * a * t^2
d= Vox*t

The Attempt at a Solution

I used Voy=2.64*sin30˚, Vox= 2.64cos30 I plugged everything into these equations, solved for t using the quadratic equation, and I got t=0.4723 but that was wrong

 

[rl.bhat]

Show your calculations.

 

[MozAngeles]

Voy=2.64sin30= 1.33

h = y0 + v0*t + 1/2 * a * t^2
-0.465= 1.33t + 1/2*(-9.8)t^2
-4.9t^2 + 1.33t+ .465=0
t= -1.33-sqrt 1.33^2-(4*-4.9*.465)/ 2*-4.9
t= .04723

 

[rl.bhat]

Voy=2.64sin30= 1.33

h = y0 + v0*t + 1/2 * a * t^2
-0.465= 1.33t + 1/2*(-9.8)t^2
-4.9t^2 + 1.33t+ .465=0
t= -1.33-sqrt 1.33^2-(4*-4.9*.465)/ 2*-4.9
t= .04723

vo, h and g are in the same direction. So they must have the same sign.

 

[MozAngeles]

Thank you so much, that helped!