Max Ball Height: No Mass Needed

[jaron]

Homework Statement

you throw a ball directly upward, giving it an initial velocity of 10.0 m/s. neglecting friction, what would be the maximum height of the ball? (explain why you do not need to know the mass of the ball)

Homework Equations

now the problem itself i understand.

we need Eg=mgh, Ek=1/2mv^2

The Attempt at a Solution

Ek=Eg
1/2mv^2 = mgh
1/2v^2 = gh
1/2(10.0)^2 = 9.81h
50/9.81 = h
h = 5.1m

i understand that we do not have mass and so it must cancel out, but i am confused as to why we do not need to know the mass?

 

[Cyosis]

What falls faster a feather or a cannon ball? (this problem assumes 0 resistance)

 

[jaron]

neglecting air friction, neither..
meaning mass doesn't matter

 

[Cyosis]

So you're saying that gravity accelerates all masses in an equal manner. This is correct. What is the one force acting upon the ball after you release it?

 

[jaron]

only gravity (in this instance because it says to neglect friction)

 

[Cyosis]

Yes, do you understand now why you don't need to know the mass of the ball?

 

[jaron]

i understand.
thank you