Math Problem Statement

The displacement (in centimeters) of a particle moving back and forth along a straight line is given by the equation of motion s = 5 sin πœ‹t + 2 cos πœ‹t, where t is measured in seconds. (Round your answers to two decimal places.) (a) Find the average velocity during each time period. (iii) [1, 1.01]

Solution

The average velocity of a particle over a time interval [t1,t2][t_1, t_2] is given by the formula:

vavg=s(t2)βˆ’s(t1)t2βˆ’t1v_{\text{avg}} = \frac{s(t_2) - s(t_1)}{t_2 - t_1}

where s(t)=5sin⁑(Ο€t)+2cos⁑(Ο€t)s(t) = 5 \sin (\pi t) + 2 \cos (\pi t).

Step 1: Compute s(1)s(1)

s(1)=5sin⁑(Ο€β‹…1)+2cos⁑(Ο€β‹…1)s(1) = 5 \sin (\pi \cdot 1) + 2 \cos (\pi \cdot 1)

=5sin⁑π+2cos⁑π= 5 \sin \pi + 2 \cos \pi

=5(0)+2(βˆ’1)=βˆ’2= 5(0) + 2(-1) = -2

Step 2: Compute s(1.01)s(1.01)

s(1.01)=5sin⁑(Ο€β‹…1.01)+2cos⁑(Ο€β‹…1.01)s(1.01) = 5 \sin (\pi \cdot 1.01) + 2 \cos (\pi \cdot 1.01)

Approximating values:

sin⁑(Ο€β‹…1.01)=sin⁑(Ο€+0.01Ο€)=βˆ’sin⁑(0.01Ο€)β‰ˆβˆ’0.0314\sin (\pi \cdot 1.01) = \sin (\pi + 0.01\pi) = -\sin (0.01\pi) \approx -0.0314

cos⁑(Ο€β‹…1.01)=cos⁑(Ο€+0.01Ο€)=βˆ’cos⁑(0.01Ο€)β‰ˆβˆ’0.9995\cos (\pi \cdot 1.01) = \cos (\pi + 0.01\pi) = -\cos (0.01\pi) \approx -0.9995

s(1.01)=5(βˆ’0.0314)+2(βˆ’0.9995)s(1.01) = 5(-0.0314) + 2(-0.9995)

=βˆ’0.157βˆ’1.999=βˆ’2.156= -0.157 - 1.999 = -2.156

Step 3: Compute the Average Velocity

vavg=s(1.01)βˆ’s(1)1.01βˆ’1v_{\text{avg}} = \frac{s(1.01) - s(1)}{1.01 - 1}

=βˆ’2.156βˆ’(βˆ’2)0.01= \frac{-2.156 - (-2)}{0.01}

=βˆ’2.156+20.01= \frac{-2.156 + 2}{0.01}

=βˆ’0.1560.01=βˆ’15.6= \frac{-0.156}{0.01} = -15.6

Final Answer:

vavgβ‰ˆβˆ’15.60 cm/sv_{\text{avg}} \approx -15.60 \text{ cm/s}

Would you like a more detailed explanation? Here are some related questions:

  1. How do we approximate sine and cosine for small angles?
  2. Why do we use the difference quotient to calculate average velocity?
  3. What is the significance of a negative average velocity?
  4. How does average velocity differ from instantaneous velocity?
  5. How would the result change for a different interval, such as [1, 1.1]?

Tip: The negative sign of the average velocity means the particle is moving in the negative direction over the given time interval.

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Math Problem Analysis

Mathematical Concepts

Trigonometry
Kinematics
Average Velocity
Sine and Cosine Functions

Formulas

v_avg = (s(t2) - s(t1)) / (t2 - t1)

Theorems

Kinematic equations for motion
Trigonometric approximations for small angles

Suitable Grade Level

Grades 11-12