Register to reply

Phase Constant

by GatorJ
Tags: constant, phase
Share this thread:
Apr2-10, 10:53 AM
P: 3
1. The problem statement, all variables and given/known data
What is the phase constant (from 0 to 2π rad) for the harmonic oscillator with the velocity function v(t) given in Fig. 15-30 if the position function x(t) has the form x = xmcos(ωt + φ)? The vertical axis scale is set by vs = 7.50 cm/s.

2. Relevant equations
x = xmcos(ωt + φ)
v=-ωxmsin(ωt + φ)

3. The attempt at a solution

From graph, vm=9.375 cm/s

vm=9.375 cm/s = ωxm


At t=0, v(0)=7.5 cm/s=-ωxmsin(φ)



φ=sin-1(7.5/-9.375)= -.927 rad

I still got it wrong and not sure where I messed up. Only thing that I can think of is that I incorrectly assumed t=0 is 7.5 cm/s and if that's the case then I don't know where to begin on this problem.
Phys.Org News Partner Science news on
Bees able to spot which flowers offer best rewards before landing
Classic Lewis Carroll character inspires new ecological model
When cooperation counts: Researchers find sperm benefit from grouping together in mice
Apr2-10, 11:15 AM
HW Helper
P: 4,435
Phase angle is always positive.
In this problem phase angle is in the fourth quadrant.
Apr2-10, 11:20 AM
HW Helper
P: 10,384
It is correct, but try to give in positive angle with the same sine: pi-phi= 4.068 rad.


Register to reply

Related Discussions
Phase constant of SHM Introductory Physics Homework 3
Phase Constant Introductory Physics Homework 4
Hmm... phase constant... Introductory Physics Homework 1
Phase Constant Introductory Physics Homework 5
Phase constant -Please help me! Introductory Physics Homework 13