Basketball Physics Question (kinematics, really )

[Femme_physics]

Basketball Physics Question (kinematics, really :) )

(I'll get back to electronics later... :) )

Homework Statement

http://img819.imageshack.us/img819/5468/bballdrawing.jpg In this drawing is depicted a quick shot from a part in a basketball game. In the drawing you see player A throwing the ball and the ball went precisely into the basket. (C)

You can see player B tried to block the ball but could not touch it.

Calculate

A) The initial speed of the ball
B) The height of the ball as soon as it passes over player B

Note: Ignore the size of the ball

Measurements are in meters

Homework Equations

Kinematics

The Attempt at a Solution

First off this is clearly goaltending therefor the block is illegal. But, I'll ignore that for the sake of physics.

I used the trajectory formula (I'm not sure how this formula is really called)

http://img228.imageshack.us/img228/174/traj.jpg And then I just plugged in the figures.

alpha = 30 degrees
y₀ = 2.1m
x₀ = 0
x = 9m
y = 3m
v₀ = ?
h = ?

http://img94.imageshack.us/img94/5097/basketballq.jpg

 

[gneill]

I think you forgot to take the square root at the end there.

 

[Femme_physics]

*smacks forehead*

Thank you! I'm just new to projectile motion so I automatically think that I made a mistake somewhere...