4 2 A particle moving along a line has position s(t) = t - 18t'm at time t seconds (for t ≥ 0). At which times is the particle instantaneously motionless (zero velocity)? Show all work.

Calculus: Early Transcendentals
8th Edition
ISBN:9781285741550
Author:James Stewart
Publisher:James Stewart
Chapter1: Functions And Models
Section: Chapter Questions
Problem 1RCC: (a) What is a function? What are its domain and range? (b) What is the graph of a function? (c) How...
icon
Related questions
Question
### Particle Motion and Instantaneous Rest

A particle moving along a line has its position described by the function \( s(t) = t^4 - 18t^2 \) meters at time \( t \) seconds (for \( t \geq 0 \)).

#### Problem
Determine the times at which the particle is instantaneously motionless (i.e., has zero velocity). Provide a detailed explanation of the solution.

#### Solution
1. **Velocity Function:**
   Velocity \( v(t) \) is the first derivative of the position function \( s(t) \). 
   
   \[
   v(t) = \frac{ds(t)}{dt}
   \]

   Compute the derivative:
   \[
   v(t) = \frac{d}{dt} (t^4 - 18t^2)
         = 4t^3 - 36t
   \]

2. **Determine where velocity is zero:**
   Set the velocity function equal to zero to find the critical points.

   \[
   4t^3 - 36t = 0
   \]

   Factor out the common term \( 4t \):
   \[
   4t(t^2 - 9) = 0
   \]

   This simplifies to:
   \[
   4t(t - 3)(t + 3) = 0
   \]

   Solve for \( t \):
   \[
   t = 0, \quad t = 3, \quad t = -3
   \]

   Since \( t \geq 0 \), we ignore the negative value \( t = -3 \).

   Therefore, the times at which the particle is instantaneously motionless are \( t = 0 \) seconds and \( t = 3 \) seconds.
Transcribed Image Text:### Particle Motion and Instantaneous Rest A particle moving along a line has its position described by the function \( s(t) = t^4 - 18t^2 \) meters at time \( t \) seconds (for \( t \geq 0 \)). #### Problem Determine the times at which the particle is instantaneously motionless (i.e., has zero velocity). Provide a detailed explanation of the solution. #### Solution 1. **Velocity Function:** Velocity \( v(t) \) is the first derivative of the position function \( s(t) \). \[ v(t) = \frac{ds(t)}{dt} \] Compute the derivative: \[ v(t) = \frac{d}{dt} (t^4 - 18t^2) = 4t^3 - 36t \] 2. **Determine where velocity is zero:** Set the velocity function equal to zero to find the critical points. \[ 4t^3 - 36t = 0 \] Factor out the common term \( 4t \): \[ 4t(t^2 - 9) = 0 \] This simplifies to: \[ 4t(t - 3)(t + 3) = 0 \] Solve for \( t \): \[ t = 0, \quad t = 3, \quad t = -3 \] Since \( t \geq 0 \), we ignore the negative value \( t = -3 \). Therefore, the times at which the particle is instantaneously motionless are \( t = 0 \) seconds and \( t = 3 \) seconds.
Expert Solution
steps

Step by step

Solved in 3 steps with 3 images

Blurred answer
Recommended textbooks for you
Calculus: Early Transcendentals
Calculus: Early Transcendentals
Calculus
ISBN:
9781285741550
Author:
James Stewart
Publisher:
Cengage Learning
Thomas' Calculus (14th Edition)
Thomas' Calculus (14th Edition)
Calculus
ISBN:
9780134438986
Author:
Joel R. Hass, Christopher E. Heil, Maurice D. Weir
Publisher:
PEARSON
Calculus: Early Transcendentals (3rd Edition)
Calculus: Early Transcendentals (3rd Edition)
Calculus
ISBN:
9780134763644
Author:
William L. Briggs, Lyle Cochran, Bernard Gillett, Eric Schulz
Publisher:
PEARSON
Calculus: Early Transcendentals
Calculus: Early Transcendentals
Calculus
ISBN:
9781319050740
Author:
Jon Rogawski, Colin Adams, Robert Franzosa
Publisher:
W. H. Freeman
Precalculus
Precalculus
Calculus
ISBN:
9780135189405
Author:
Michael Sullivan
Publisher:
PEARSON
Calculus: Early Transcendental Functions
Calculus: Early Transcendental Functions
Calculus
ISBN:
9781337552516
Author:
Ron Larson, Bruce H. Edwards
Publisher:
Cengage Learning