# A force of 5 pounds stretches

*label*Humanities

*timer*Asked: Apr 22nd, 2014

*account_balance_wallet*$5

**Question description**

A force of 5 pounds stretches a spring 1 foot. A mass weighing 6.4 pounds is attached to the spring, and the system is then immersed in a medium that offers a damping force numerically equal to 1.6 times the instantaneous velocity.

I calculated that the equation of motion if the mass is initially released from rest from a point 1 foot above the equilibrium position is : x(t) = e^(-4t) [-cos(3t) - 4/3sin(3t)]

Please help me find the equation of motion in the form x(t) = Ae^(?*?t) sin(sqrt(?^2 - ?^2) +* )

-When i tried getting this i got A =4/3, w^2 = 25, lambda = 16, pheta = arctan(3/4)

Find the first time at which the mass passes through the equilibrium position heading upward

_________________S

Please help me find the equation of motion in the form x(t) = Ae^(?*?t) sin(sqrt(?^2 - ?^2) +* )

x(t) = _____________________

## Tutor Answer

Brown University

1271 Tutors

California Institute of Technology

2131 Tutors

Carnegie Mellon University

982 Tutors

Columbia University

1256 Tutors

Dartmouth University

2113 Tutors

Emory University

2279 Tutors

Harvard University

599 Tutors

Massachusetts Institute of Technology

2319 Tutors

New York University

1645 Tutors

Notre Dam University

1911 Tutors

Oklahoma University

2122 Tutors

Pennsylvania State University

932 Tutors

Princeton University

1211 Tutors

Stanford University

983 Tutors

University of California

1282 Tutors

Oxford University

123 Tutors

Yale University

2325 Tutors