# Physics

posted by
**charlie**
.

For a child's swing in lightly damped SHM, I am given the time period and a value for g; (as well as the mass.)

with just these, can i rearrange the equation:

T (4s)= 2pi times sqrt l/g

to calculate the length of the swing?

I believe i have (3.98m), but the question says to ignore the mass of the ropes. I'm worried i should use mass, but it seems uneccessary.

Any help appreciated.