Rubentheran
May 18, 2011, 02:24 AM
Question : A ship is sailing 45m/s due south-east, while the wind speed is 20m/s from west.Find the magnitude and the direction of the wind velocity relative to the ship
Answer given is 33.94 m/s ; Angle is 339.6.
I'm stuck at the middle.someone help out this.
This what I do :
let s=ship
w=wind
V=velocity
So, resolve in terms of vector
Vs = 45cos45 I - 45sin45 j
Vws = 20 I
Vws = Vw - Vs
Vw = 20 I + 45cos45 I -45sin45 j
= 51.82 I - 31.82 j
Magnitude = sguare root of (51.82^2 + 31.82^2 )
= 60.81 m/s
this what answer I get and its wrong.the correct answer is 33.94 m/s and angle of 339.6.Can someone really guide me the steps and working ? Thanks you very much for your concern.
Answer given is 33.94 m/s ; Angle is 339.6.
I'm stuck at the middle.someone help out this.
This what I do :
let s=ship
w=wind
V=velocity
So, resolve in terms of vector
Vs = 45cos45 I - 45sin45 j
Vws = 20 I
Vws = Vw - Vs
Vw = 20 I + 45cos45 I -45sin45 j
= 51.82 I - 31.82 j
Magnitude = sguare root of (51.82^2 + 31.82^2 )
= 60.81 m/s
this what answer I get and its wrong.the correct answer is 33.94 m/s and angle of 339.6.Can someone really guide me the steps and working ? Thanks you very much for your concern.