Physics

[sethw38]

A ball is thrown vertically upward with a
speed of 26.4 m/s from a height of 2.0 m.
How long does it take to reach its high-
est point? The acceleration of gravity is
9.81 m/s2.
Answer in units of s

[jake-the-peg]

you need to use Newtons laws of motion

v=u+at

v²=u²+2as

or

x=ut+½at²

it's final speed (V) is going to be 0 at it's highest point a is the acceleraion due to gravity (don't forget its negative here) you have the intitial speed(U) and you don't care about the height

so you have V,U a and you want t

select the right equation and plug in the numbers solve for t

[factor-fiction]

Good answer jake.
Am I right in saying the initial height of 2m is a red herring here?

[factor-fiction]

When you've worked it out, seth, if you put the answer on here we'll let you know whether it matches ours

[vascop]

factor,
Yes the initial height is not relevant, UNLESS there is a second part which asks what this maximum height is. Then you would need to add the initial height to the value of the distance moved from initial point to the point where velocity is zero. Draw a diagram.