Projectile Motion: Find Initial Velocity of Diver Springing From 3m Board

[ladolce]

Homework Statement

A diver springs upward from a board that is three meters above the water. At the instant she contacts the water her speed is 9.10 m/s and her body makes an angle of 75.0° with respect to the horizontal surface of the water. Determine her initial velocity, both magnitude and direction.

Homework Equations

Kinematics equations :)

The Attempt at a Solution

I already got 4.9 m/s as the magnitude of the vector, but can't seem to get the direction in degrees!

 

[Doc Al]

What's the horizontal component of her velocity?

 

[ladolce]

i just used the (9.1)squared=v initial squared +2(-9.8)(-3) and got the v initial magnitude...i don't know how to get the components is why I'm confused actually

 

[Doc Al]

Hint: You have her final speed and angle. Use it!

 

[ladolce]

ok, so i got 3.85 as vx and for vy =8.79 but how does that help me?

 

[Doc Al]

ok, so i got 3.85 as vx

Show how you got that value.

but how does that help me?

Does the horizontal component of velocity change as the diver falls?

 

[ladolce]

Haha I got the answer...thanks for your help =)