IIT JEE-AIEEE 2012, Entrance Notifications, Study Tips, Engineering Preparation, Practice Test Papers, Experts Advice

Ask iit jee aieee pet cbse icse state board community

Discussion Response Post to: The ultimate challenge in Mechanics from Feynmann

Forum Index -> Mechanics -> View Full Question

Author

Message

Soumen Goswami (2446)

Forum Expert

total posts: 1777
Offline

The problem is best solved in plane polar coordinates. (For an analysis of motion in plane polar coordinates please refer to "Fundamentals of Mechanics" by I E Irodov)
Velocity of B in the frame of A,
(dr/dt)e_r + (r(d

/dt)e_th = [u - vcos

]e_r - (- vsin

)e_th

(dr/dt) = u-vcos

------------------(1)
And
r(d

/dt) = vsin

----------------(2)

Dividing (1) by (2) and rearranging,
(1/r)dr = (u/v)cosec

- cot

^r (1/r)dr = _pi/2

^theta(u/v)cosec

- _pi/2

^thetacot

ln(r/d) = ln[(cosec

- cot

)^u/v/sin

]
r/d = (1 - cos

)^u/v]/(sin

)^(u/v)+1

Was quite an enjoyable problem ... can you tell me its source??

All men dream but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find that it was vanity; but the dreamers of the day are dangerous men, for they may act their dream with open eyes to make it possible.

Like 0 people liked this

Free Sign Up!

Preparing for IIT-JEE ?

Arihant Revision Package for IIT JEE - Books, Practice Tests + Rank Predictor

@ INR 1,995/-

For Quick Info