Question

someone kelp me please!!!!

Answer 1

Please check my second question.....

Answer 2

please check my method and calculations with a calculator........

Answer 3

Do you not have a calculator?

Answer 4

is my method correct?????O_O

Answer 5

@IrishBoy123 can you please check my work??????:)

Answer 6

Part A)
Her velocity relative to the short is equal:
\[v=\sqrt{(1.2\frac{km}{h})^{2}+(2\frac{km}{h})^{2}} \approx 2.3\frac{km}{h}\]
Which by my calculation should give you an angle of:
\[\tan^{-1} (\frac{ 1.2 }{ 2 }) \approx 31^{o}\]

Answer 7

The method you choose for part b seems correct... using the known velocity across the river coupled with the width of the river to find the travel time.... then using that travel time to calculate the vertical distance downstream the boat has gone.

Answer 8

t your part one doesn't look correct......hold up let me upload the first question....:)

Answer 9

However for the time i found 46.08s... but this problem is using 2 significant figures so 46s is probably sufficient

Answer 10

it's because i think the numbers that your inputting aren't so accurate....

Answer 11

Crap your right I was using the wrong horizontal velocity (2 km/s) :( lemme recalc

Answer 12

let me upoad the first question, may take some time....

Answer 13

Ok I got 2.8 (rounded from 2.77) km/s and 26 degrees (rounded from 25.6)

Answer 14

yes 26 is what i got.

Answer 15

so for part b like i was saying the idea is correct, but i got different numbers (see above) that I did use the correct velocity to calculate (2.5 not 2)

Answer 16

try plug in those new numbers....

Answer 17

so in 46 seconds the boat travelled downstream a distance d=vt=(1.2*1000/3600) m/s * 46s = 15.33s or roughly 15 seconds (again 2 sig figs.... I dont know if your teacher is a stickler for that)

Answer 18

darn i meant meters... 15.33 or just 15 m

Answer 19

I did YumYum i plugged in the right numbers and am getting slightly different answers in my calulations

Answer 20

Ok for part c) its a little bit more involved but still not too bad hold on....

Answer 21

Yes YumYum i posted those corrected numbers above

Answer 22

let me upload my part c.....

Answer 23

so basically speaking part C) is looking for you to correct for the downward drift by aiming the boat upwards

Answer 24

please check my east and north signs, are they correct? at the bottom of the page!!!

Answer 25

i think it should have been (N29E), what do you think.????

Answer 26

don't worry about medals, your about to get plenty from me ^_^

Answer 27

So you correctly note the hypoteneuse is of magnitude 2.5 km/s because that is max speed of her boat... which gives you an angle of sin^-1(1.2/2.5) ~28.68~29degrees

Answer 28

i wrote 29degrees!!!

Answer 29

then you found the horizontal velocity to be 2.5^2=v^2+1.2^2 or v=sqrt(2.5^2-1.2^2)~2.19~2.2km/h

Answer 30

i don't know why i wrote 2.2"KM/h"

Answer 31

it should have been 2.2Km up in the north.....

Answer 32

as for the formatting of the direction.... that I am a little unsure about since it has been a while... but your angle is correct so i have to leave that to you unfortunately :(

Answer 33

does it all look right?!?!?!?!?

Answer 34

so if you take north as your main direction you would be heading at an angle 90-29=61degrees east from the north or 29degrees north from the east... something like that

Answer 35

So yea i agree it all looks good... so far so good

Answer 36

aight thanks!!! Please come online more often, i might need your help.....24/7 :"D
Thanks!!!!

Answer 37

now part d is confusingly worded in my opinion but if I understand it correctly than it is easy... just reproduce what you did in part b using your new horizontal velocity to calculate the time to travel across the river here

Answer 38

since she will arrive directly at the farmers market that will be the TOTAL travel time to the farmers market using this route

Answer 39

it ok, i'll ask irishboy123....chill out

Answer 40

ok i looked back up above and in the first possible path she ended up approx 15m to the south of the market

Answer 41

so use her walking velocity to calculate the time it will take her to walk that distance north to the farmers market..... add it to the time it took her to cross the river... and that will give you the TOTAL time of the trip using this route

Answer 42

The conclusion should be clear at that point which is the best route to talk (quickest)

Answer 43

take*

Answer 44

Thanks!!

Answer 45

Your welcome :D

Answer 46

don't mind but i need to confirm with irishboy ^_^

Answer 47

cuz 2 is better than 1 :D

Answer 48

i do it all the time....:)

Answer 49

yea no probs i have seen irish boy he is good.... i couldve sworn i saw you two working earlier but when i saw this post again there was no content which is why i jumped in

Answer 50

take it easy man!!! ^_^
come more often, we need people like you here on OS!!! :)

Answer 51

Yea I do when I have some spare time, but i am in university currently and have my own work and research to be doing.

Answer 52

Thanks for all your help!!!! you sound very very smart tho!!! :)

Answer 53

understood!!!

Answer 54

Alright Thanks for everything, i hope i see you more often ^_^ Cheers!!!

Answer 55

Thank you :D and you are very welcome I will when I can

Answer 56

Yes!!!!! :D