two masses 8 kg and 12 kg are
attached to an ideal string passed over
a fixled smooth pulley. When it is
released from rest, what will be the
distance travelled by each mass in
2 second?
Answers
The given system of two masses and a pulley can be represented as shown in the following figure:
Smaller mass, m
1
=8 kg
Larger mass,m
2
=12kg
Tension in the string=T
Mass m
2
, owing to its weight, moves downward with acceleration, and mass m
1
moves upward.
Applying Newton’s second law of motion to the system of each mass:
For mass m 1 :
The equation of motion can be written as:
T–m 1
g=ma… (i)
For mass m2:The equation of motion can be written as:m 2
g–T=m2a … (ii)
Adding equations (i) and (ii), we get:
(m2−m1)g=(m1+m2)a
The given system of two masses and a pulley can be represented as shown in the following figure:
Smaller mass, m
1
=8 kg
Larger mass,m
2
=12kg
Tension in the string=T
Mass m
2
, owing to its weight, moves downward with acceleration, and mass m
1
moves upward.
Applying Newton’s second law of motion to the system of each mass:
For mass m 1 :
The equation of motion can be written as:
T–m 1
g=ma… (i)
For mass m2:The equation of motion can be written as:m 2
g–T=m2a … (ii)
Adding equations (i) and (ii), we get:
(m2−m1)g=(m1+m2)a