- #1
1irishman
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1. Homework Statement
Two cars are parked beside each other, facing in opposite directions. Car 1 accelerates at 5m/s^2 up to a max. speed of 25m/s, and Car 2 accelerates at 4m/s^2 up to a max. speed of 24m/s. How much time has elapsed when the cars are 200m apart?
2. Homework Equations
v=d/t
vf^2=vi^2+2ad
vf=vi+at
3. The Attempt at a Solution
Car 2
------
576=8d
d=72m
it takes car 2 6seconds to travel 72m
Car1
--------
625=10d
d=62.5m
it takes car 1 5seconds to travel 62.5m
So, the cars are 134.5m apart at this stage. They need to travel 200m-134.5m=65.5m before they are 200m apart, yes? The answer is 6.83 seconds, but i don't understand how they got that. please help?
Two cars are parked beside each other, facing in opposite directions. Car 1 accelerates at 5m/s^2 up to a max. speed of 25m/s, and Car 2 accelerates at 4m/s^2 up to a max. speed of 24m/s. How much time has elapsed when the cars are 200m apart?
2. Homework Equations
v=d/t
vf^2=vi^2+2ad
vf=vi+at
3. The Attempt at a Solution
Car 2
------
576=8d
d=72m
it takes car 2 6seconds to travel 72m
Car1
--------
625=10d
d=62.5m
it takes car 1 5seconds to travel 62.5m
So, the cars are 134.5m apart at this stage. They need to travel 200m-134.5m=65.5m before they are 200m apart, yes? The answer is 6.83 seconds, but i don't understand how they got that. please help?