alpha?????????

A block slides down a smooth track of height 50cm and then enters into a loop of radius 20cm from which a symmetrical section of 2α has been removed.Find angle α such that after leaving the circle at A and flying through air,the block will reach point B?

7 Answers

33
Abhishek Priyam ·

By writing energy conservation between initial ht and A find speed at A... direction will be tangential.. at A after that a projectile solve it like a projectile and write condition o reach B from that u will get α..

Try this theres nothing conceptual.. all calculations and i hate doing that :P

24
eureka123 ·

okzzzzzzzz

33
Abhishek Priyam ·

cosα=1/2

[7]

24
eureka123 ·

yup

33
Abhishek Priyam ·

U want soln...[7]

33
Abhishek Priyam ·

Only in short i am giving..

velocity at A is tangential to circle.. so velocity there will make an angle α with the horizontal..

now its projectile with u at an angle α and range should be 2Rsinα (distance b/w A and B)

from range eqn get a relation between α and u

u=(10R/cosα)1/2

now energy conservation b/w initial pt and A

mgH=mgR(1+cosα)+1/2mu2

put the value of u ..
u=(10R/cosα)1/2

and solve to get α=0,cos-11/2
notice significance of α=0 in the answer

cHeErs.. :)

33
Abhishek Priyam ·

For projectile motion b/w A and B..

Superposition method gives the relation easily..

Now in ΔABC.. applying sin law..

ut=2Rsinα/cosα=5t2/sinα..

eliminating t gives the relation u=(10R/cosα)1/2 which i used above..

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