A signal f(t) has the Laplace transform F(s) = (−8s + 27)/(s² + 12s + 35). Use the initial value theorem to find f(0⁺), the value of f(t) just after t = 0.
Laplace transforms worksheet with answers
Find the inverse Laplace transform f(t) of F(s) = 12s/(s² + 36) with a table of transform pairs, and evaluate f(1).
Find f(t) for F(s) = (4s + 36)/(s² + 10s + 25) and evaluate f(0.25).
Find f(t) for F(s) = (s + 14)/(s² + 8s + 25) by completing the square, and evaluate f(0.3).
A system is described by the differential equation y″ + 6y′ + 5y = 2u′ + 5u, 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 = 0.6 s. Find g(0.6).
A system is described by the differential equation y″ + 4y′ + 13y = 2u′ + 4u, 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⁺) = −8
- 2. f(1) = 11.52
- 3. f(0.25) = 2.292
- 4. f(0.3) = 0.9737
- 5. g(0.6) = 0.4738
- 6. g(0.1) = 1.564
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