How to find mass in an Atwood machine

[iyanna]

Homework Statement

A pumpkin and a weight are attached to a frictionless pulley. As the 5kg weight is released, the pumpkin accelerates down at 4.65 m/s^2 to the ground. What is the mass of the pumpkin? [/B]

Homework Equations

How do I find the mass?

The Attempt at a Solution

T=m1g
ma=m2g-T
m=m2g-T/a
m=m2g-49/4.65
m=10.53-m2g
m-10.53=m2g
10.53+5=15.53
m2=1.57kg

 

[haruspex]

It says the pumpkin accelerates downwards. Does that make it more or less than 5kg?

 

[iyanna]

It says the pumpkin accelerates downwards. Does that make it more or less than 5kg?

More

 

[haruspex]

You don't make it clear, but I assume you are using m ( or m1) for the mass of the weight and m2 for the pumpkin.
If T is the tension in the rope, what are the forces acting on the pumpkin? What "F=ma" equation does that give you? Same questions for the weight.

 

[Kamisama]

I think your formula is off.

Shouldn't it be m2 = (ma + T) / g ?

 

[haruspex]

I think your formula is off.

Shouldn't it be m2 = (ma + T) / g ?

How is that different from

ma=m2g-T

?