# Homework Help: Kinematics Problem on a particle

1. Feb 3, 2010

### zewei1988

1. The problem statement, all variables and given/known data

The motion of a human body through space can be modeled as the motion of a particle at the body's center of mass. The components of the position of an athlete's center of mass from the beginning to the end of a certain jump are described by the following two equations, where t is the time at which the athlete lands after taking off at t = 0.
xf = 0 + (10.6 m/s)(cos 18.5°)t
0.230 m = 0.600 m + 0 + (10.6 m/s)(sin 18.5°)t - (9.80 m/s2)t2

Identify his vector position.

2. Relevant equations

3. The attempt at a solution
I tried to solve for t in the second equation and got a value of 0.783s, after which I put this value into the first equation and solve for x and got 7.87m for the i direction. I did not really know what to put in for the displacement along the y-axis.

2. Feb 3, 2010

### kuruman

Where did this equation come from and what does it mean?

3. Feb 3, 2010

### zewei1988

it was just given. Anyway i got the answer. they were asking for the initial displacement. thanks for your help. is there anyway to close this thread?

4. Feb 3, 2010

No closure.