1. Speed question

Runner #1 is 35m ahead of Runner #2.
Runner #1 travels at 1.65m/s and Runner #2 travels at 1.85m/s.
Both run in the same direction.
From where they begin, how far does Runner #2 travel before he catches up with Runner #1, how long does it take?

I know i have to use variables, but i'm lost. Any help please

2. Originally Posted by Raj
Runner #1 is 35m ahead of Runner #2.
Runner #1 travels at 1.65m/s and Runner #2 travels at 1.85m/s.
Both run in the same direction.
From where they begin, how far does Runner #2 travel before he catches up with Runner #1, how long does it take?

I know i have to use variables, but i'm lost. Any help please
You want to find what time (and therefore location) where the runners are at the same spot. Runner #1 is 35 meters ahead of the other one, so use a distance equation...

$d=rt$

$d_1+D=d_2$

$r_1t+D=r_2t$

$1.65t+35=1.85t$

$35=0.2t$

$t=175$

At 175 seconds into the "race", Runner #1 and Runner #2 are in the same spot. Plug $t=175$ into the original equation: $1.65t+35=1.85t$

$323.75=323.75$

3. You don't have to use any equation or formula for this question. We will just use our imagination

(This solution is similar to my post here)

First, imagine the scene as you're on the ground, standing, looking at the runners. You see that they're 35 m away and running at the same direction at 1.85 m/s and 1.65 m/s.

Now, imagine the scene as you are Runner #2. You're 35 m behind Runner #1. You both start running. Ignore the grounds. What do you see? You see that Runner #1 gets closer at 0.2 m/s! (it's 1.85 - 1.65). We just calculated the relative speeds. And now, he's 35 m ahead and coming closer at 0.2 m/s. When would you meet? It's so easy,
$V = \frac{x}{t}$
$0.15 = \frac{35}{t}$
$t = \frac{35}{0.2}$
$t = \frac{350}{2} = 175$ seconds

Now you work the rest

4. Originally Posted by wingless
You don't have to use any equation or formula for this question. We will just use our imagination

(This solution is similar to my post here)

First, imagine the scene as you're on the ground, standing, looking at the runners. You see that they're 35 m away and running at the same direction at 1.85 m/s and 1.65 m/s.

Now, imagine the scene as you are Runner #2. You're 35 m behind Runner #1. You both start running. Ignore the grounds. What do you see? You see that Runner #1 gets closer at 0.2 m/s! (it's 1.85 - 1.65). We just calculated the relative speeds. And now, he's 35 m ahead and coming closer at 0.2 m/s. When would you meet? It's so easy,
$V = \frac{x}{t}$
$0.15 = \frac{35}{t}$
$t = \frac{35}{0.2}$
$t = \frac{350}{2} = 175$ seconds

Now you work the rest
I really have to remember this way of solving, test in 2 hours so

Thanks (again)