Another simple velocity question.

[cherryrocket]

[SOLVED] Another simple velocity question.

"Juanita left on a walk 45 min ago. She is traveling at 4.5 km/h. How fast must you travel to catch up to her in 1.0h"?

Juanita t=45 min v=4.5 km/h
d=vt = (4.5km/h)(0.75h) = 3.375 km

Me -
v=d/t = (3.375km)/1.0h = 3.4 km/h

I must travel at 3.4 km/h to catch up to her in 1 hour.
Correct?

 

[Sourabh N]

for the 1 hour you chased Jua... she must also have traveled.

 

[cherryrocket]

REVISION to simple velocity Q.

***REVISION***
Juanita left on a walk 45 min ago. She is traveling at 4.5 km/h. How fast must you travel to catch up to her in 1.0h"?

Juanita t=45 min +1.0h min v=4.5 km/h
d=vt = (4.5km/h)(1.75h) = 7.8 km

Me -
v=d/t = (7.8km/1.0h) = 7.8 km/h

I must travel at 7.8 km/h to catch up to her in 1 hour.

Is it this? For some reason the answer still doesn't seem right...

 

[learningphysics]

You aren't rounding your answer properly. It should be 7.875km/h, which is 7.9km/h when rounded to 2 sig.figs.

 

[cherryrocket]

So then I did get the right answer, just didn't round properly, right? Thanks!

 

[learningphysics]

So then I did get the right answer, just didn't round properly, right? Thanks!

yeah. no prob. But why did you think your answer was wrong?

 

[cherryrocket]

I don't know, I just thought it was too easy to be the right answer... does that make sense? lol

ps. how do you close a thread when a question is solved?

 

[learningphysics]

I don't know, I just thought it was too easy to be the right answer... does that make sense? lol

ps. how do close a thread when a question is solved

Yeah, I understand that.

I'll mark the thread as "SOLVED". It won't close it, but that's ok.