An athlete swims the length $L$ of a pool in a time $t_1$ and makes the return trip to the starting position in a time $t_2$. If she is swimming initially in the positive x direction, determine her average velocities symbolically in (a) the first half of the swim

help me analyze this @rajathsbhat ? :)

Question

An athlete swims the length $L$ of a pool in a time $t_1$ and makes the return trip to the starting position in a time $t_2$. If she is swimming initially in the positive x direction, determine her average velocities symbolically in (a) the first half of the swim

help me analyze this @rajathsbhat ? :)

anonymous · Answer

OK

lgbasallote · Answer

do we use speed = distance/time?

anonymous · Answer

yes, but that's not the ques.

lgbasallote · Answer

aww :9

lgbasallote · Answer

:( *

anonymous · Answer

It's just that the avg velocity of the swimmer is positive in the first half & -ve in the second. That's all.

lgbasallote · Answer

i see i see..makes sense...so how?

anonymous · Answer

You see they have asked you to take the direction in which she starts to swim as the +ve X direction

anonymous · Answer

so deltax will be +ve during that time.

lgbasallote · Answer

uhh maybe the solution can make sense? o.O

lgbasallote · Answer

im not really good with terms...im better in analyzing algebra lol

anonymous · Answer

I'll try to draw you a diagram

lgbasallote · Answer

ugh please no diagrams o.O just solution

lgbasallote · Answer

diagrams tend to confuse me a lot...the only time i was able to get it was when i studied calculus and it took me a hard time

anonymous · Answer

I'll write it with my own hand & scan it

lgbasallote · Answer

uhmm sure...ill try to understand it...but i really think the solution can help me better o.O

anonymous · Answer

Well, as for thee sol, it is "positive"

lgbasallote · Answer

do we use distance/time?

lgbasallote · Answer

is it $$\frac{L}{t_1}$$

anonymous · Answer

No, we use
v=delta x/t1
 =+L/t1

lgbasallote · Answer

so just add +?

anonymous · Answer

For the return swim, it would be
v=-L/t1

anonymous · Answer

Yes, cause the direction is very important in this Ques

lgbasallote · Answer

shouldnt it be $$-\frac{L}{t_2}?$$

anonymous · Answer

Ahh, sorry, yes, it should.

mathslover · Answer

average velocity for the first half of the swim= L/T1

lgbasallote · Answer

what about for round trip? $$\frac{2L}{t_2 - t_1}?$$

mathslover · Answer

0 by velocity she did not change position

anonymous · Answer

No, the avg vel for the round trip is 0

lgbasallote · Answer

what about average speed?

lgbasallote · Answer

that's the correct symbolism?

mathslover · Answer

average speed for the round trip= 2L/(T1+T2)

lgbasallote · Answer

oh..plus

anonymous · Answer

2L/t1+t2

mathslover · Answer

yes u missed ... no problem

lgbasallote · Answer

great//thanks ^_^

anonymous · Answer

Awesome.

anonymous · Answer

yw :)

mathslover · Answer

well as u commented there diagrams make the question complicated for you .. i will prefer you to just draw a simple diagram first ... like that of this one

mathslover · Answer

in physics without diagrams there is nothing to analyze with. :(

anonymous · Answer

true, mathslover, very true.