A signal f(t) has the Laplace transform F(s) = (−5s + 23)/(s² + 5s + 14). Find the initial slope f′(0⁺) with the initial value theorem.
Laplace transforms worksheet with answers
A signal f(t) has the Laplace transform F(s) = (5s² + 24s + 53)/(s(s + 3)(s + 6)). Use the initial value theorem to find f(0⁺), the value of f(t) just after t = 0.
Find f(t) for F(s) = (s + 7)/(s² + 2s + 10) by completing the square, and evaluate f(0.2).
Find f(t) for F(s) = (3s + 20)/(s² + 8s + 16) and evaluate f(0.5).
A system obeys y″ + 5y′ + 6y = 6·u(t), with y(0) = 3 and y′(0) = 0. At t = 0 a step input u(t) = 4 is applied. Use the Laplace transform to find y(0.1).
A system is described by the differential equation y″ + 4y′ + 20y = 3u′ + u, with input u(t) and output y(t). Find its transfer function G(s) = Y(s)/U(s) (zero initial conditions) and evaluate the impulse response g(t) at t = 0.1 s. Find g(0.1).
Answer key
- 1. f′(0⁺) = 48
- 2. f(0⁺) = 5
- 3. f(0.2) = 1.6
- 4. f(0.5) = 0.9473
- 5. y(0.1) = 3.025
- 6. g(0.1) = 1.864
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