(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Scenario 1: Mass suspended from dasphot (damper) and spring

Mass=M

Damping Coefficient=c

Spring Constant=K

Scenario 2: Mass supported by dashpot (damper) and spring

Mass=M

Damping Coefficient=c

Spring Constant=K

In both cases, derive the equations of motion assuming that each mass is at some point displaced from static equilibrium.

Justify the use of positive or negative signs in the problem

2. Relevant Concepts

D'almbert's principle

Fspring= -kx

Fdamping= cx'

3. The attempt at a solution

Sign Conventions are throwing me for a loop. The equation will in both cases be of the form:

mx"+cx'+k(deltastatic+x)=weight

solutions will be of the form:

x(t)=Ae^(a+lamda*i)t + Be^(a-lambda*i)t

BUT HOW DO I JUSTIFY THE SIGN CONVENTIONS!? Free body diagrams are really confusing me in what is a relatively simple problem

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Free Vibration- Viscous Damping

Can you offer guidance or do you also need help?

Draft saved
Draft deleted

**Physics Forums | Science Articles, Homework Help, Discussion**