# maximum displacement in a mass-spring

#### SuperSaiyan3

7+ Year Member
Kaplan stated in a practice passage that the max. displacement in a mass-spring is TWO TIMES that of the amplitude

why would this be true? How would you know that? What would the amplitude even be??

#### soby10

10+ Year Member
5+ Year Member
In simple harmonic motion the x (displacemnt)= +A to -A. Amp in this way is 1 period. Think about it the particle or whatever travels up and then down the same distance 2X. So it is 2x the A value. So in finding the value of x use x=A cos theata which in turn is equiv. to A cos omega*time

#### matth87

In simple harmonic motion the x (displacemnt)= +A to -A. Amp in this way is 1 period. Think about it the particle or whatever travels up and then down the same distance 2X. So it is 2x the A value. So in finding the value of x use x=A cos theata which in turn is equiv. to A cos omega*time
The time from +A to -A is not 1 period, it is a half period.

The time from +A to -A to +A again would be 1 period.

#### matth87

Kaplan stated in a practice passage that the max. displacement in a mass-spring is TWO TIMES that of the amplitude

why would this be true? How would you know that? What would the amplitude even be??
I always defined Amplitude as maximum displacement from the equilibrium.

Are you comparing 1 or 2 diff springs here?

#### Tokspor

Kaplan stated in a practice passage that the max. displacement in a mass-spring is TWO TIMES that of the amplitude

why would this be true? How would you know that? What would the amplitude even be??
Would you mind posting the exact question? I'd like to look at the wording. The maximum displacement from equilibrium would only be the amplitude. The maximum displacement from fully compressed to fully stretched would be twice the amplitude.

OP

#### SuperSaiyan3

7+ Year Member
Would you mind posting the exact question? I'd like to look at the wording. The maximum displacement from equilibrium would only be the amplitude. The maximum displacement from fully compressed to fully stretched would be twice the amplitude.
Don't quite recall where the question is, but I think that's what they meant.

The maximum displacement would be 2A (amplitude).

Good explanations all around, and yes, Crest to trough (+A to -A) is HALF the period.

Thank you!!

-SS3

#### soby10

10+ Year Member
5+ Year Member
Yeah sorry typo.. ment to write in 1/2..but yeah that's how i think about in terms of periods