# Acceleration problem

1. Mar 3, 2007

### elton_fan

1. The problem statement, all variables and given/known data
In a 100 m race, Maggie and Judy cross the finish line at the same time, both taking 10.2 s. Accelerating uniformly, Maggie takes 2.00 s and Judy 3.00 s to attain maximum speed, which they maintain for the rest of the race.
What is the acceleration of each sprinter?
2. Relevant equations
what is the equation to find the acceleration

3. The attempt at a solution

i couldn't understand the problem

2. Mar 3, 2007

### denverdoc

As counterintuitive as it may seem, ties do not imply that the final speed is the same. The most general kinematic eqn for circumstances of linear acceleration is:

Xf=Xi+V(init)t+1/2a*t^2,

but in this case the t's in the eqn are different.

We can call them t1 and t2.

The distance covered during t1 and t2= 100m
the velocity at the end of the acceleration phase muct equal the velocity during the sustained phase. See if that helps.

PS: solving the two girls cases are independent.