How do u find the height of an object thrown straight up

1. Mar 27, 2006

dcgirl16

how do u find the height of an object thrown straight up if u are only given that it is thrown with a velocity of 30m/s

2. Mar 27, 2006

arildno

Energy conservation..

3. Mar 27, 2006

dcgirl16

so how do i do it

4. Mar 27, 2006

arildno

Write down the equation for energy conservation, perhaps?

5. Mar 27, 2006

blimkie

how exactly is the question worded?

6. Mar 27, 2006

daniel_i_l

What is the initial kinetic energy? If that energy is turned to potential energy, how high is the object?

7. Mar 27, 2006

ThomasW

because energy is conserved, all the kinetic energy will be converted to potential energy
KE = PE
1/2 mv^2 = mgh
1/2 v^2 = gh
1/2 (30)^2 = 9.8 h

8. Mar 27, 2006

arildno

ThomasW:
Let the original poster try to solve the problem on her own before providing a full solution.

Welcome to PF, by the way.

9. Mar 27, 2006

ThomasW

alrite, arildno
i'll do that from now on

10. Mar 28, 2006

benzun_1999

u can also use equations of motion
ie is v^2=u^2+2gs
where v is final velocity here it is 0,
where u is initial velocity(given)
where g is acceleration due to gravity
where s is the distance or height reached.