sign up I login
 advanced
refer a friend - earn nickels!!

Ask & Discuss Questions with Community & Experts

Moderation Team
Ask iit jee aieee pet cbse icse state board community Discussion Response Post to: Another interesting 1d question
Forum Index -> Mechanics -> View Full Question like the article? email it to a friend.  
Author Message
bladeX (68)

Hot goIITian

Olaaa!! Perrrfect answer. 10  [19 rates]

bladeX's Avatar

total posts: 157    
offline Offline
THERE ARE TWO MOTION :
for the upside motion -
F= MG +KV^2      Mdv/dt = MG + KV^2      Mdv/ds .  ds/dt=Mg + KV^2
Mv  /(Mg KV^2)  dv =  ds
[v0 ][o ] MV/(MG +KV^2). dv =   [ 0][l ]  ds
(try the integration if your maths is strong and  you'll  get  -)
M[ ln (MG/(MG + KVo^2) )]/2k  =   L ( L is the max height attained ) ............1
now for  downward  motion
m dv/dt = MG - KV^2 
mV / (mg - kv^2) dv =  ds
integrate both side
[o ][v' ] mV/( mg - kv^2) = [0 ][L] ds
again try and you'll get
m[ ln ( | mg - kv'^2 |/mg ] / 2k = L  .......................2
compare 1 and 2
ln (mg / (mg + KV^2) ) = ln (mg -kv^2 /mg)

v'  =  [ MGKV0^2 / ( MGK + K^2 V0^2) ]

V' = V0/ (1+ KV0^2 /MG )
V' is your answer definetely ... write if you can't understand my solution i might elaborate it further .
     



WALK NOT AS IF YOU RULE THE WORLD...
BUT AS IF YOU DON'T CARE WHO RULES IT....

MAN WOULD DO NOTHING IF HE WAITED UNTIL HE COULD DO IT SO WELL THAT NO OTHER BEING CAN FIND FAULT WITH IT..................NEWMAN
 this reply: 5 points  (with Olaaa!! Perrrfect answer.   in 1 votes )   [?]
 
You have to be logged on to rate
  
 

Top Offers for goIITians
Correspondence Courses
Brilliant Tutorials
Narayana Institute
Aakash Institute
Classroom/Crash Courses
Narayana - Kota , Delhi , Others
Brilliant Tutorials - Class , Crash
Aakash Institute - Medical , Engg
Online Test Series
Brilliant Tutorials
Narayana Institute
Aakash Institute
Mahesh Tutorials
AMITY      Sri Chaitanya