Packaged dropped from Hot Air Balloon

[dvdqnoc]

Homework Statement

A Hot air balloon is traveling vertically up-
ward at a constant speed of 2.6 m/s. When
it is 19 m above the ground, a package is
released from the balloon.
The acceleration of gravity is 9.8 m/s^2.
After it is released, for how long is the
package in the air? Answer in units of s.

Homework Equations

http://www.glenbrook.k12.il.us/gbssci/phys/Class/1DKin/U1L6a1.gif

The Attempt at a Solution

I tried doing X = .5at^2 + vit and using -2.6, but it didnt work.

 

[learningphysics]

you can solve the problem directly with:

d = v1*t + (1/2)at^2

what is d? what is v1? what is a?

 

[dvdqnoc]

well a is -9.8 because of gravity.

Vi is 2.6, but its the opposite direction of falling. So what do I do with it?

d is 19 m.

I don't know how to use that equation because the Velocity is upward, but the object is falling DOWN.

 

[learningphysics]

well a is -9.8 because of gravity.

Vi is 2.6, but its the opposite direction of falling. So what do I do with it?

d is 19 m.

I don't know how to use that equation because the Velocity is upward, but the object is falling DOWN.

d is -19m. because the object drops a distance of 19m. ie: vertical displacement = final height - initial height = 0m - 19m = -19m.

plug in a = -9.8, vi=2.6 and d = -19 into the equation...

solve for t.