**Problem 1 (Discontinuous Forcing):** Suppose we have an undamped spring-mass system, where a 0.3 kg mass is attached to a spring with a spring constant of 30 N/m. At \( t = 0 \), the mass is disturbed from rest by an oscillating motor, which supplies a force of \( 3 \cos 9.2t \, \text{N} \) to the system. After 10 seconds, the motor is switched off. We can model the forcing with the discontinuous function: \[ f(t) = \begin{cases} 3 \cos 9.2t & \text{if } 0 \le t < 10 \\ 0 & \text{if } t \ge 10 \end{cases} \] Tasks: (a) **Write down the initial value problem** that describes this spring-mass system. (b) **Solve the IVP** from part (a) and express your answer as a piecewise function. **Hint:** First solve the IVP for \( 0 \le t < 10 \), then for \( t \ge 10 \), and combine the two answers. Make sure the resulting function is differentiable at \( t = 10 \) (i.e., the functions and their derivatives must match up there). (c) Use graphing software (such as Desmos.com) to **graph the solution** from part (b), and use the graph to describe the motion of the spring-mass system. (d) **Repeat parts (a)–(c)** with the forcing function: \[ f(t) = \begin{cases} 3 \cos 10t & \text{if } 0 \le t < 10 \\ 0 & \text{if } t \ge 10 \end{cases} \] **What do you notice about the motion now?**

Advanced Engineering Mathematics
10th Edition
ISBN:9780470458365
Author:Erwin Kreyszig
Publisher:Erwin Kreyszig
Chapter2: Second-order Linear Odes
Section: Chapter Questions
Problem 1RQ
icon
Related questions
Question
100%
**Problem 1 (Discontinuous Forcing):** 

Suppose we have an undamped spring-mass system, where a 0.3 kg mass is attached to a spring with a spring constant of 30 N/m. At \( t = 0 \), the mass is disturbed from rest by an oscillating motor, which supplies a force of \( 3 \cos 9.2t \, \text{N} \) to the system. After 10 seconds, the motor is switched off. We can model the forcing with the discontinuous function:

\[
f(t) = 
\begin{cases} 
3 \cos 9.2t & \text{if } 0 \le t < 10 \\
0 & \text{if } t \ge 10 
\end{cases}
\]

Tasks:

(a) **Write down the initial value problem** that describes this spring-mass system.

(b) **Solve the IVP** from part (a) and express your answer as a piecewise function.

   **Hint:** First solve the IVP for \( 0 \le t < 10 \), then for \( t \ge 10 \), and combine the two answers. Make sure the resulting function is differentiable at \( t = 10 \) (i.e., the functions and their derivatives must match up there).

(c) Use graphing software (such as Desmos.com) to **graph the solution** from part (b), and use the graph to describe the motion of the spring-mass system.

(d) **Repeat parts (a)–(c)** with the forcing function:

\[
f(t) = 
\begin{cases} 
3 \cos 10t & \text{if } 0 \le t < 10 \\
0 & \text{if } t \ge 10 
\end{cases}
\]

**What do you notice about the motion now?**
Transcribed Image Text:**Problem 1 (Discontinuous Forcing):** Suppose we have an undamped spring-mass system, where a 0.3 kg mass is attached to a spring with a spring constant of 30 N/m. At \( t = 0 \), the mass is disturbed from rest by an oscillating motor, which supplies a force of \( 3 \cos 9.2t \, \text{N} \) to the system. After 10 seconds, the motor is switched off. We can model the forcing with the discontinuous function: \[ f(t) = \begin{cases} 3 \cos 9.2t & \text{if } 0 \le t < 10 \\ 0 & \text{if } t \ge 10 \end{cases} \] Tasks: (a) **Write down the initial value problem** that describes this spring-mass system. (b) **Solve the IVP** from part (a) and express your answer as a piecewise function. **Hint:** First solve the IVP for \( 0 \le t < 10 \), then for \( t \ge 10 \), and combine the two answers. Make sure the resulting function is differentiable at \( t = 10 \) (i.e., the functions and their derivatives must match up there). (c) Use graphing software (such as Desmos.com) to **graph the solution** from part (b), and use the graph to describe the motion of the spring-mass system. (d) **Repeat parts (a)–(c)** with the forcing function: \[ f(t) = \begin{cases} 3 \cos 10t & \text{if } 0 \le t < 10 \\ 0 & \text{if } t \ge 10 \end{cases} \] **What do you notice about the motion now?**
Expert Solution
Solution: a

The undamped spring mass system is given by my+ky=ft.

Here, m=0.3 and k=30

The undamped spring mass system becomes 0.3y''+30y=3cos9.2tif 0t<100if t10.

b. For 0t<10, the non-homogeneous equation is 0.3y''+30y=3cos9.2t.

It can be written as y''+100y=10cos9.2t.

Solve the homogeneous equation: y''+100y=0

The characteristic equation is

m2+100=0m=±10i

steps

Step by step

Solved in 4 steps with 1 images

Blurred answer
Recommended textbooks for you
Advanced Engineering Mathematics
Advanced Engineering Mathematics
Advanced Math
ISBN:
9780470458365
Author:
Erwin Kreyszig
Publisher:
Wiley, John & Sons, Incorporated
Numerical Methods for Engineers
Numerical Methods for Engineers
Advanced Math
ISBN:
9780073397924
Author:
Steven C. Chapra Dr., Raymond P. Canale
Publisher:
McGraw-Hill Education
Introductory Mathematics for Engineering Applicat…
Introductory Mathematics for Engineering Applicat…
Advanced Math
ISBN:
9781118141809
Author:
Nathan Klingbeil
Publisher:
WILEY
Mathematics For Machine Technology
Mathematics For Machine Technology
Advanced Math
ISBN:
9781337798310
Author:
Peterson, John.
Publisher:
Cengage Learning,
Basic Technical Mathematics
Basic Technical Mathematics
Advanced Math
ISBN:
9780134437705
Author:
Washington
Publisher:
PEARSON
Topology
Topology
Advanced Math
ISBN:
9780134689517
Author:
Munkres, James R.
Publisher:
Pearson,