Two blocks A and B of same masses attatched with a light spring are suspended by a string as shown in figure .Find the acceleration of block A and block B just after cut the string .
Answers
Answer :-
To Find :-
→ Acceleration of block "A" and "B" .
Explanation:-
According to the question -
→ Mass of both blocks is same .
(1) Before cut the string ( refer to attachment )
Before cut the string tension (T) , spring force (kx) and gravitational force (mg) is working on block "A" ,
Before cut the string there is no acceleration in both blocks .
hence ,
→ T - kx - mg = 0 .....eq.(1) ( on block A)
and ,
→ kx - mg = 0 ( on block B)
→ kx = mg [ put in eq.(1) ]
→ T - mg - mg = 0
→ T = 2mg
now,
(2) Just after cut the string ( refer to the attachment )
After cutting the string these is Acceleration in both block .( After cut the string Tension is removed on block "A" )
hence ,
• On block "B"
• On block "A"
Note - After cut the string these is no normal contact force .( so neglect it )
Question :
Two blocks A and B of same masses attatched with a light spring are suspended by a string as shown in figure .Find the acceleration of block A and block B just after cut the string .
Solution :
See the following attachment...
The image shows the F.B.D diagram.
Referring to the diagram,
We can derive the following equations :
Note :
After the string is cut, the tension will become zero but the spring force i.e, kx will remain same.
This is a crucial point to note while solving.
Now draw the F.B.D again and solve.
Equations :
Therefore the :
- acceleration of the block A = 2g
- acceleration of the block B = 0.