Help with my physics...

[lbinator]

Question: An airplane travels at 1800km at a speed of 1000km/h. It then encounters a headwind that slows it down to 850km/h for the next 2300km. What was the average speed of the plane for this trip?

The answer according to the sheet is 550km/h, it doesn't explain how this answer was achieved but when I tried it my answer was 909.921671 Km/h.

Can anybody get 550km/h? or was I actually right?

[GuidoHunter]

Re: Help with my physics...

First attempt I got 909, too, but that's just by doing total distance/total time, so nobody else try that. =)

--Guido

http://andy.mikee385.com

[Reach]

Re: Help with my physics...

hmm, well, logically, the average can't possibly be 550 since the plane doesn't go any slower than 850 mph XD

It's wrong.


Your answer is correct.

[TheRapingDragon]

Re: Help with my physics...

When I checked it I got 911, it's a conspiracy.

[lbinator]

Re: Help with my physics...

hmm, well, logically, the average can't possibly be 550 since the plane doesn't go any slower than 850 mph XD

It's wrong.


Your answer is correct.

Wow I can't believe I didn't notice that, thanks everybody.

[Tasselfoot]

Re: Help with my physics...

lol at Reach.... but yea... this is some pretty easy ****.

what I want to know is how the plane magically went from 1000km/s to 850km/s without any kind of period of acceleration change.

y'know, that 2nd part of the 3 part question with "the plane decelerated from 1000 to 850 over 1000 miles at a fixed rate of deceleration." then again, the average speed if it was a fixed deceleration would be the average of the two... meh.


I know! The plane's engines died and freefell for 6 seconds. lol. now THAT would make the problem amusing. wonder if they'd make you calculate the terminal velocity of the plane. assuming air resistance is 0, of course. but, alas, it wouldn't change the horizontal velocity. :-/.

where are our fun problems with parabolic trajectories and ledges and crap.

[TheRapingDragon]

Re: Help with my physics...

what I want to know is how the plane magically went from 1000km/s to 850km/s without any kind of period of acceleration change.

It then encounters a headwind that slows it down to 850km/h

Is that not why?

[Tasselfoot]

Re: Help with my physics...

it would still be gradual.... unless we have like, the Wind of God pushing into it or something.

[Squeek]

Re: Help with my physics...

Is that not why?

Nothing is instantaneous in an analogue world.

There's a reason straight lines are banned from graphs of functions in mathematics. That's instantaneous motion assuming the X-axis represents time.

[Reach]

Re: Help with my physics...

Straight lines are BANNED?

lmao.

They just don't exist, since a slope of infinity is not possible.

B&

[Kit-]

Re: Help with my physics...

Nothing is instantaneous in an analogue world.

There's a reason straight lines are banned from graphs of functions in mathematics. That's instantaneous motion assuming the X-axis represents time.

Unless, of course, we believe in the Planck Postulate.

[Squeek]

Re: Help with my physics...

Straight lines are BANNED?

lmao.

They just don't exist, since a slope of infinity is not possible.

B&

Ya, they're b&

Using terminology everyone can understand here.