Object falling down and object falling up

[physicN00Bz]

Homework Statement

A object A falling down at terminal velocity of 20 m/s, at 1000m above the ground another object B fly at it at an initial velocity of 125 m/s.

a) how much time before object A hits object B?

Homework Equations

X = Xo + Vo(t) + 1/2AT^2

G = 9.8 m/s^2

The Attempt at a Solution

using the equation i found it takes object A 12.385 second to fall down from 1000
m while object B 6.321 second to reach 1000 m

but I am not sure how i can find out when they will hit each other.

 

[rl.bhat]

Suppose they meet at a height x from the ground. Then the distance moved by A is 1000 - x and distance move by B is x. A is moving with uniform velocity where as B is moving with the acceleration. When they meet, they must have taken the same time. So write two equations and solve for x.

 

[SammyS]

Does an object falling at terminal velocity accelerate? Why not?

So, you time for object A is incorrect.

Object B will not reach a height of 1000 m.

An object launched downward at 125 m/s from a 1000 m altitude, will reach the ground in 6.396 s, ignoring air resistance.