Physics Homework Help (acceleration & velocity)

[Kiwi]

Hello,

I was wondering if anyone could help me with the following question:

How long does it take for a shoe to drop 75 m from rest? What is the final velocity?

I have that the acceleration is equal to gravity at -9.8 m/s squared and that the distance is 75 m and the intial velocity is zero but I can't get much further than that. Thanks very very much for your time!

 

[Pyrrhus]

Hello,

I was wondering if anyone could help me with the following question:

How long does it take for a shoe to drop 75 m from rest? What is the final velocity?

I have that the acceleration is equal to gravity at -9.8 m/s squared and that the distance is 75 m and the intial velocity is zero but I can't get much further than that. Thanks very very much for your time!

Look up kinematic equations

 

[Simfish]

y = 75 - 4.9t^2.
Solve for y = 0.

 

[Tide]

We're all waiting for the other shoe to drop! (Sorry - couldn't resist!)

BTW - I think air drag will be an important factor in this one but I'm sure your textbook isn't interested in that complication.

 

[h8ter]

Yea, in most High School Physics text, air resistance is neglected.

 

[Sjuckett848]

(Vf)^2=(Vo)^2+2ad

Vf=Final Velocity
Vo=Initial Velocity
a=Acceleration
d=Distance

*This equation does not include air drag

 

[cdhotfire]

ya just use the equation mentioned above and you should be able to get the right awnser.