Velocity of block B in the given arrangement is 300mm/sec towards right. Then velocity of A will be
A
200mm/sec
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
B
100mm/sec
No worries! Weāve got your back. Try BYJUāS free classes today!
C
450mm/sec
No worries! Weāve got your back. Try BYJUāS free classes today!
D
150mm/sec
No worries! Weāve got your back. Try BYJUāS free classes today!
Open in App
Solution
The correct option is A200mm/sec
Assume rightward direction to be +ve
For pulley 1, v1=vB=vC+vD2 vC=0 since that end of the string is fixed. ⇒vD=2vB−−(1)
For pulley 2, v2=vA=vE+vF2 vE=vD ⇒vA=2vB+vF2−−(2) (using (1))
Pulley 3 is fixed ⇒vG=vH=vA
But vF=vG ∴vF=−vA−−(3)
(because direction is opposite to that of A)
Substituting (3) in (2), vA=2vB−vA2 ⇒3vA=2vB ⇒vA=2vB3=2×300mm/sec3 ⇒vA=200mm/sec