Accelerating Masses: Solving for Acceleration using m1, m2, and g"

[Priyadarshini]

Homework Statement

Homework Equations

a= (m2g)/(m1+m2)

The Attempt at a Solution

Which is option 4.
But the answer doesn't match

 

[Doc Al]

Show how you got your answer.

 

[Priyadarshini]

Show how you got your answer.

The formula for acceleration here is:
m2g/(m1+m2)
So shouldn't that be the answer?

 

[Doc Al]

The formula for acceleration here is:
m2g/(m1+m2)

Why do you think that is the formula? How did you derive that?

 

[Priyadarshini]

Why do you think that is the formula? How did you derive that?

For m1:
T=m1a
the normal reaction force in the upwards direction = m1g
For m2:
m2g-T=m2a
so,
m2g-m1a=m2a
m2g=m1a+m2a
so acceleration = m2g/(m1+m2)

 

[Doc Al]

For m1:
T=m1a

Note that the acceleration here is the horizontal acceleration.

the normal reaction force in the upwards direction = m1g
For m2:
m2g-T=m2a

Here the acceleration is the vertical acceleration. (What must that equal?)