# 100-meter dash

1. Sep 18, 2007

### nerdgirl909

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

A sprinter can accelerate with constant acceleration for 3.40 s before reaching top speed. He can run the 100-meter dash in 10 s.

What is his speed as he crosses the finish line? (in m/s)

2. Relevant equations

kinematic equations

3. The attempt at a solution

a (acceleration) is positive and nonzero for the first 3.40 s

a is zero for the last 6.60 s

2. Sep 18, 2007

### learningphysics

What is the distance covered in the first 3.40s? What is the distance covered in the last 6.60s ?

3. Sep 18, 2007

### bugbug

I think that this is how you would solve this. The distance can be found because it is a case of two equtions and two unknowns.

Last edited: Sep 18, 2007