How Long Before the Apple Core Hits the Ground?

[Nicolaus]

Homework Statement

A child sitting in a tree throws an apple core from where he is perched (4 m high) with a velocity of 5 m/s [35 degrees above horizontal] and it hits the ground next to his friend.
How long before the core hits the ground?

Homework Equations

dy = vy(initial)t + 1/2at
quadratic eqn.

The Attempt at a Solution

Would I calculate the x-y components of the initial velocity then plug in the initial y velocity to the first aforementioned eqn then solve for t using the latter eqn?

 

[FeynmanIsCool]

Don't mind that comment! read it too fast, I did not take angle into account, I thought he was throwing it straight down. Whoops! that's embarrassing, back to high school physics for me

 

[frogjg2003]

Your first equation is wrong. You're forgetting the dy(initial) term.
Other than that, you're right.

 

[frogjg2003]

Do not do what FaynmanIsCool wrote. The final velocity is not 0, he didn't account for the launch angle, and he has the wrong sign for a.

 

[FeynmanIsCool]

This is a good example of your problem with different factors:
http://physics.bu.edu/~duffy/semester1/c3_projectile.html