Calculating the Free Fall of Two Balls

[Robdog]

Homework Statement

Two ball are dropped from 5m high, Use 10 m/s^2 for the magnitude of the acceleration due to gravity.

Homework Equations

How do i start?

The Attempt at a Solution

not sure on how to start so i haven't attempted:(

 

[Astronuc]

What is the question or problem to be solved?

Neglecting air resistance, they both accelerate at the same rate.

One might find this a useful reference - http://hyperphysics.phy-astr.gsu.edu/hbase/traj.html

 

[Robdog]

the problem asks how much time is elapsed during the fall of the 5.0m at a rate of 10m/s^2

Im sure there is an equation for this but i don't know which one or where to find it...

 

[Astronuc]

If something starts at rest, i.e. with zero velocity, how far does is travel in time, t, if the acceleration is constant.

See - http://hyperphysics.phy-astr.gsu.edu/hbase/acons.html

The same concept applies for horizontal (x) or vertical (y) motion, provided the acceleration is constant.

 

[Robdog]

so... y=1/2at^2... y equal to the height of 5m? if so then i get 5m=1/2(10m/s^2)T^2 which = square root of 5.00s which = 2.24s? but the that answer is still wrong. What did i do wrong.

 

[Robdog]

o nvm should be the square root of 1.00s... ill try that, wow i feel like an idiot... i need to sleep

 

[Astronuc]

Well - you figured it out. Do get some sleep, and refer to hyperphysics when the mind is more relaxed.