- #1
- 580
- 0
Refer to diagram:ritwik06 said:Sorry guys. I posted an empty thread by mistake due to power failure. Here is the question.
Homework Statement
Point A moves uniformly with velocity v so that the vector v is continually "aimed" at point B which in its turn moves rectilinearly and uniformly ith velocity u <v. At the initial moment of time v is perpendicular to u and the points are separatd by distance k. How soon will the points meet?
The Attempt at a Solution
ritwik06 said:Sorry guys. I posted an empty thread by mistake due to power failure
Well, I haven't studied kinematics in very much details, not even circular motion. But I am able to solve simple questions on circular motion. I know simple usage of basic calculus. Please guide me to solve this, as its been a long time since i hav been trying this question.
tiny-tim said:ah … and I thought your dog ate it!
You don't need "kinematics", or even acceleration, just a clear head (and enough light to see the problem!).
You simply need to know what θ is (or tanθ) …
and you can work that out because you know exactly where B is at time t, and you just subtract (x,y) from that.
tiny-tim said:Hi ritwik06!
(x,y) is the position of A … x along the x-axis, and y up the y-axis.
As you say, B is at position (k,ut).
So the vector AB is (k - x, ut - y), and so tanθ = (ut - y)/(k - x).
ritwik06 said:So nobody could answer this here as well?
malawi_glenn said:you have not done an attempt to solution.
Read it several times.ZapperZ said:Read this:
https://www.physicsforums.com/showthread.php?t=94379
Zz.
ritwik06 said:so nobody could solve it right now, eh?