(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A hiker throws a stone from the upper edge of a vertical cliff. The stone ' s initial velocity is 25.0 m/s directed at 40.0 degrees with the face of the cliff, as shown in Fig. 3.1. The stone hits the ground 3.75 s after being thrown and feels no appreciable air resistance as it falls. the height of the cliff is closest to

Here is the link to the picture: http://img10.imageshack.us/img10/8058/58525486.jpg [Broken]

2. Relevant equations

3. The attempt at a solution

So what I first did was break the velocity into its vertical and horizontal components,

25.0sin40=16.06m/s(y0)

25.0cos40=19.15m/s(x0)

We know the time it takes to hit the gound is 3.75 seconds

I got its Vy( final velocity) by using the following equation vy=vosina-gt

vy=16.0sin40-9.8(3.75s)

=-26.46m/s

Here is where I start getting lost, I wanted to solve for deltay using the following formula;

vf^2=vi^2+2aDeltay

(-24.46)^2-(16.06)^2/2(-9.8).. and I got some funky answer, the answer to the problem is 141.

Can someone walk me through how to get that answer, thank you!

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# Homework Help: Projectile motion of a thrown rock

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