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EGR 1101: Unit 11 Lecture # 1. Applications of Integrals in Dynamics: Position, Velocity, & Acceleration (Section 9.5 of Rattan/Klingbeil text). Differentiation and Integration. Recall that differentiation and integration are inverse operations.
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EGR 1101: Unit 11 Lecture #1 Applications of Integrals in Dynamics: Position, Velocity, & Acceleration (Section 9.5 of Rattan/Klingbeil text)
Differentiation and Integration • Recall that differentiation and integration are inverse operations. • Therefore, any relationship between two quantities that can be expressed in terms of derivatives can also be expressed in terms of integrals.
Position, Velocity, & Acceleration Position x(t) Derivative Integral Velocity v(t) Derivative Integral Acceleration a(t)
Today’s Examples • Ball dropped from rest • Ball thrown upward from ground level • Position & velocity from acceleration (graphical)
Graphical derivatives & integrals • Recall that: • Differentiating a parabola gives a slant line. • Differentiating a slant line gives a horizontal line (constant). • Differentiating a horizontal line (constant) gives zero. • Therefore: • Integrating zero gives a horizontal line (constant). • Integrating a horizontal line (constant) gives a slant line. • Integrating a slant line gives a parabola.
Change in velocity = Area under acceleration curve • The change in velocity between times t1 and t2 is equal to the area under the acceleration curve between t1 and t2:
Change in position = Area under velocity curve • The change in position between times t1 and t2 is equal to the area under the velocity curve between t1 and t2:
EGR 1101: Unit 11 Lecture #2 Applications of Integrals in Electric Circuits (Sections 9.6, 9.7 of Rattan/Klingbeil text)
Review • Any relationship between quantities that can be expressed using derivatives can also be expressed using integrals. • Example: For position x(t), velocity v(t), and acceleration a(t),
Energy and Power • We saw in Week 6 that power is the derivative with respect to time of energy: • Therefore energy is the integral with respect to time of power (plus the initial energy):
Current and Voltage in a Capacitor • We saw in Week 6 that, for a capacitor, • Therefore, for a capacitor,
Current and Voltage in an Inductor • We saw in Week 6 that, for an inductor, • Therefore, for an inductor,
Today’s Examples • Current, voltage & energy in a capacitor • Current & voltage in an inductor (graphical) • Current & voltage in a capacitor (graphical) • Current & voltage in a capacitor (graphical)
Review: Graphical Derivatives & Integrals • Recall that: • Differentiating a parabola gives a slant line. • Differentiating a slant line gives a horizontal line (constant). • Differentiating a horizontal line (constant) gives zero. • Therefore: • Integrating zero gives a horizontal line (constant). • Integrating a horizontal line (constant) gives a slant line. • Integrating a slant line gives a parabola.
Review: Change in position = Area under velocity curve • The change in position between times t1 and t2 is equal to the area under the velocity curve between t1 and t2:
Applying Graphical Interpretation to Inductors • For an inductor, the change in current between times t1 and t2 is equal to 1/L times the area under the voltage curve between t1 and t2:
Applying Graphical Interpretation to Capacitors • For a capacitor, the change in voltage between times t1 and t2 is equal to 1/C times the area under the current curve between t1 and t2: