Question

A wombat runs south in a straight line with an average velocity of 5 m/s for 4 minutes and then with an average velocity of 4 m/s for 3 minutes in the same direction . Would those both be the initial and Final velocities ?

Answer 1

does the question states if it comes to a stop? if it doesn't state anything of the sort then I'd say yes and I'll solve for whatever with those as initial and final velocities

Answer 2

Btw what is the displacement is what the question is

Answer 3

asking

Answer 4

Yeah, it doesn't mention anything about stopping

Answer 5

displacement is velocity times time taken

Answer 6

I got -3.5?

Answer 7

convert minutes to seconds then work it out

Answer 8

i got 1920m as distance due south = displacement

Answer 9

Ohhh I missed that . Now I just got -210

Answer 10

how is displacement negative? how did u work it out?

Answer 11

there's no such thing as negative displacement or distance

Answer 12

I did final veloctiy - initial velocity * time / 2

Answer 13

why?

Answer 14

Our teacher told us to use this long equation. Just tell me how you would work it?

Answer 15

ok we're looking for displacement... right?
in that case, what is displacement... speed x time.
Initially, the average speed was 5m/s and that lasted a period of 4 minutes
then average speed after 4 minutes is 4m/s for a period of 3 minutes.
We have speed, we have time... But our units don't match, hence...
4minutes=240seconds
3minutes=180seconds
Now we can safely find total displacement = (5*240) + (4*180)
=1200+720
=1920

I hope that made some sense :/

Answer 16

sorry i forgot the units.... 1920m due south

Answer 17

Yes that did make sense ! thank you! I have one more thing to ask

Answer 18

k

Answer 19

This problem says a falling skydiver slows from a speed of 52 m/s to 8m/s in .8 sec as the parachute opens. Would if make sense to get a change in velocity that is negative since he is slowing down? Are those even velocities?

Answer 20

hmm... the change in velocity won't be negative, I'm saying this cos I can't figure out why it should be negative but it could be... i won't conclude on this but I'll let u know once i find out what the right thing is

Answer 21

Alright alright

Answer 22

what is change in velocity?

Answer 23

final velocity - initial velocity.... now tell me what u think?

Answer 24

i think i have my conclusion... and it is yes, you could say there was a negative velocity change there

Answer 25

I thought so! Thanks man you were a great deal of help! Hopefully I can ace my test tomorrow!

Answer 26

I could say the change in velocity was 44m/s... but was the velocity increasing or decreasing? the negative gives us an idea of whether the velocity was increasing or decreasing so yeah ;) that's my conclusion :D

Answer 27

Alright sounds good! :D Thank you so much!!!

Answer 28

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Answer 29

Awesome! I'll check it forsure!

Answer 30

hey I wanna make a youtube channel and put math and physics videos there... wanna help out?

Answer 31

as well as tech videos ;)