BITSAT 2019 Slot 2 Solved Paper

For perfectly elastic collision,
total momentum before collision = total momentum after collision
i.e. m.u+

3m

4

×0=mvx+

3m

4

.vy
⇒4u=4vx+3vy ........(i)
Coefficient of restitution,⇒1=

vy−vx

u−0

[

∵ux=v

anduy=v

]
u=vy−vx ........(ii)
Solving Eqs. (i) and (ii), we have
vx=

u

7

and uy=

8u

7

∴

λy

λx

=

h∕mvy

h∕ 3m 4 .vx

=

3

4

.

vx

vy

=

3

4

.

u∕7

8u∕7

=

3

32