What Speed Does the Athlete Land in Long Jump?

[zman2011]

Homework Statement

During a high school track meet, an athlete performing the long jump runs and leaps at an angle of 25 degrees and lands in a sand pit 8.8 m from his launching point. If the launch point and landing point are at the same height, y=0m, with what apeed does the athlete land?

Homework Equations

The Attempt at a Solution

Im completely stumped. any help would be appreciated.

 

[mvantuyl]

Are you familiar with the range formula?

 

[zman2011]

no i am not.

 

[zman2011]

can anyone tell me what the range formula is?

 

[mvantuyl]

R = ((v₀)² sin(2$$\theta$$₀)) / g

Rearranging this formula and solving for v0 will give you the initial velocity. You can figure out the final velocity from there.

 

[zman2011]

well then how do i find initial velocity to put it in.

 

[zman2011]

i didnt see the second part of that. sorry. thank you

 

[zman2011]

im having trouble with this. i keep getting initial velocity as a decimal

 

[Jebus_Chris]

Maybe you aren't substituting/manipulating properly.

$$x = \frac{v_o^2sin2\theta}{g}$$
$$v_o=\sqrt{\frac{xg}{sin2\theta}}$$