Bengaltiger
Badges: 0
Rep:
?
#1
Report Thread starter 13 years ago
#1
A bird is capable of flying at 80Km/h . It wishes to fly to its nest which is due east of its present position. There is a wind blowing from the north-west at 70Km/h. Find the direction in which the bird must fly to reach its nest.
0
reply
Spenceman_
Badges: 0
Rep:
?
#2
Report 13 years ago
#2
Draw a diagram.

You want to draw the birds resultant velocity vector and you want this to be going directly East. However, no matter which way the bird flies, he will be pushed South-East at 70km/h and since it doesn't matter in which order you add vectors to get the resultant, let's start by drawing on this 70km/h vector. Now the problem is saying...at what angle do I draw on the 80km/h vector such that the resultant is horizontal. Provided you know how to add two vectors it shouldn't be difficult.
0
reply
Bengaltiger
Badges: 0
Rep:
?
#3
Report Thread starter 13 years ago
#3
(Original post by Spenceman_)
Draw a diagram.

You want to draw the birds resultant velocity vector and you want this to be going directly East. However, no matter which way the bird flies, he will be pushed South-East at 70km/h and since it doesn't matter in which order you add vectors to get the resultant, let's start by drawing on this 70km/h vector. Now the problem is saying...at what angle do I draw on the 80km/h vector such that the resultant is horizontal. Provided you know how to add two vectors it shouldn't be difficult.
Yeh, i mean i tried that, but i get the wrong anwser....??
0
reply
Bengaltiger
Badges: 0
Rep:
?
#4
Report Thread starter 13 years ago
#4
Hmmm,

It seems that i have my diagram wrong. Is it possible if you can draw a quick diagram? I mean, i cant seem to draw it???
0
reply
Bengaltiger
Badges: 0
Rep:
?
#5
Report Thread starter 13 years ago
#5
(Original post by Widowmaker)
|Vw| = 70
|Vb| = 80
ehrr....I just had a quick look again and i dont quite agree with the diagram. Shouldnt the velocity of the bird be towards east, and not the velocity of the bird relative to wind??

Because if this diagram is correct, then i dont understand why it is.
0
reply
Christophicus
Badges: 18
Rep:
?
#6
Report 13 years ago
#6
Apologise for the slight error. Misread the question.

Right. I've re-done the diagram.

|bVw| = 80
|Vw| = 70

=> 80/sin45 = 70/sin([email protected]) = 70/[email protected]
=> [email protected] = 70sin45
=> [email protected] = 70sin45/80
=> @ = 52 degrees
Attached files
0
reply
Bengaltiger
Badges: 0
Rep:
?
#7
Report Thread starter 13 years ago
#7
ahh!

Now it makes sence. Thanks.
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

University open days

  • Norwich University of the Arts
    Postgraduate Open Day Postgraduate
    Thu, 23 Jan '20
  • SOAS University of London
    Development Studies, Interdisciplinary Studies, Anthropology and Sociology, Languages, Cultures and Linguistics, Arts, Economics, Law, History, Religions and Philosophies, Politics and International Studies, Finance and Management, East Asian Languages & Cultures Postgraduate
    Sat, 25 Jan '20
  • University of Huddersfield
    Undergraduate Open Day Undergraduate
    Sat, 25 Jan '20

How many uni open days have you been to/did you go to?

0 (62)
26.96%
1 (36)
15.65%
2 (40)
17.39%
3 (31)
13.48%
4 (16)
6.96%
5 (19)
8.26%
6 (6)
2.61%
7+ (20)
8.7%

Watched Threads

View All
Latest
My Feed