What is the ball's maximum height?

[Casey314stl]

Homework Statement

A ball is thrown upward.
What is its maximum height? Its initial
vertical speed is 10.8 m/s and the acceleration
of gravity is 9.8 m/s^2
Neglect air resistance.

Answer in units of m

Homework Equations

dfinal=dintial+vfinalΔt+ 1/2averageaccelerationΔt^2 or v^2final=v^2initial +2averageaccelerationΔd

The Attempt at a Solution

14.2463

 

[mtayab1994]

No remember that since the object is traveling up it will have a negative speed therefore:

Vf^2=u^2+2is

 

[Casey314stl]

No remember that since the object is traveling up it will have a negative speed therefore:

Vf^2=u^2+2is

what does u and is stand for?

 

[mtayab1994]

u and v are vectors v is the final speed which in your case will be 0 because the kinetic energy will be 0 at the maximum height so you will be left with 0=speed of the ball -2(speed of gravity)s.

 

[Casey314stl]

so how do i use this to find the height?

 

[mtayab1994]

0=(initial speed)^2-2(speed of gravity)s then once you have this down just solve the equation.

 

[Casey314stl]

0=(initial speed)^2-2(speed of gravity)s than once you have this down just solve the equation.

I am solving for Vf^2 which is vertical speed final?
so I plug in 0-2(10.8)=-21.6?

 

[gneill]

Homework Statement

A ball is thrown upward.
What is its maximum height? Its initial
vertical speed is 10.8 m/s and the acceleration
of gravity is 9.8 m/s^2
Neglect air resistance.

Answer in units of m

Homework Equations

dfinal=dintial+vfinalΔt+ 1/2averageaccelerationΔt^2 or v^2final=v^2initial +2averageaccelerationΔd

The Attempt at a Solution

14.2463

Your second equation looks promising. In more compact terms:

v_f² = v_i² + 2*a*d

where v_i is the initial velocity, v_f the final velocity, a is the acceleration and d is the distance. The distance d is what you're looking for. What values will you assign to the other variables?