Runner and a bird heading towards finish line

[learningphysics]

so i then get

.0177935943D=.0146627566D + .0019208211

i then get .0031308377D = .0019208211

D = .6135166636 km

that is the D then i solve for t of the equation

t = .6135166636/68.2

You should divide by 56.2 right? your d looks right...

 

[anglum]

why divide by 56.2?

im tryin to see how long it takes for the car goin 68.2km/h to catch up?

 

[learningphysics]

how long does it take car traveling 68.2km/h to become even with a car that is traveling in another lane at 56.2km/h if the front bumpers are initially 131 m apart


i have tried this so far

do i need to convert the 131 m to . 131 km??

d = 56.2km/h * t

and

d +131 = 68.2 km/h * t

Since you're solving for time sub. d from the first equation into the second...

56.2t + 0.131 = 68.2t

solve for t.

 

[learningphysics]

why divide by 56.2?

im tryin to see how long it takes for the car goin 68.2km/h to catch up?

The times are equal... you can also do (d+0.131)/68.2 it's the same time...

 

[anglum]

ahhh that makes total sense and now i got the correct answer as 39.3seconds

thanks learning

i am going to post a new thread on one last question if u don't mind