<p>Okay brainiacs, test your physics knowledge on this one!</p>
<p>In a 100-m race, Maggie and Judy cross the finish line in a dead heat, both taking 10.2 sec. Accelerating uniformly, Maggie took 2.00 sec and Judy 3.00 sec to attain maximum speed, which they maintained for the rest of the race.</p>
<p>(a) What was the acceleration of each sprinter?</p>
<p>(b) What were their respective maximum speeds?</p>
<p>(c) Which sprinter was ahead at the 6.00 sec mark, and by how much?</p>
<p>As you can tell, I really suck at physics, and I desperately need help :( If anyone could explain and answer any of these, I would be most appreciative! Thanks and don't be afraid to post if you have any questions/suggestions/comments</p>
<p>Forget this thread.. I finally figured it out lol.. thanks for whoever was trying to help though</p>
<p>Maggie:
Vf=at=2a
d(while accelerating)=.5at^2=.5(Vf/2)(2^2)=magnitude(Vf)^2 (the value of vf and d while accelerating are the same, but the units aren't...just so happens to work out this way)
d(at maximum speed)=Vft=Vf(10.2-2)=8.2Vf
Total distance=100=Vf^2+8.2Vf; Vf^2+8.2-100=0, solve quadratic
Vf=6.708m/s
a=Vf/2=3.35ms^-2</p>
<p>JudyVf=at=3a
d(while accelerating)=.5at^2=.5(Vf/3)(3^2)=1.5(Vf)^2<br>
d(at maximum speed)=Vft=Vf(10.2-3)=7.2Vf
Total distance=100=1.5Vf^2+7.2Vf; 1.5Vf^2+7.2Vf-100=0
Vf=6.11m/s
a=2.037ms^-2</p>
<p>Too lazy to find the stuff at 6 sec; basically, find the distance traveled while accelerating (because they both accelerate for less than 6s), subtract the time accelerating from 6s, and use taht time to find distance traveled at max speed; add the distances together and compare the two racers.</p>
<p>Edit: oops...just late...</p>
<p>lol.. thanks anyway, and once again, you're here to help! I appreciate it</p>