So I got this Project called Finding the Dew Point it says I get a can that is shiny I just what to know why does the can have to be shiny
I think I chose the wrong subject I don't if I did or didn't I very sorry if I did chose the wrong subject

Ahanging spring stretches by 35.0 cm when an object of mass 450 g is hung on it at rest. in this situation, we define its position as x = 0. the object is pulled down an additional 18.0 cm and released from rest to oscillate without friction. what is its position x at a moment 84.4 s later? express your answer in cm.