A signal f(t) has the Laplace transform F(s) = (−7s + 5)/(s² + 3s + 3). 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) = 5/(s(s² + 4s + 12)). Use the final value theorem to find the value f(∞) that f(t) settles to.
Find f(t) for F(s) = 50/(s(s + 4)(s + 5)) by partial fractions, and evaluate f(0.1).
Find f(t) for F(s) = (6s + 26)/(s² + 8s + 16) and evaluate f(0.1).
A system is described by the differential equation y″ + 6y′ + 25y = 9u, 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 = 0.4 s. Find g(0.4).
A system obeys y″ + 5y′ + 6y = 12·u(t), with y(0) = 3 and y′(0) = 0. At t = 0 a step input u(t) = 1 is applied. Use the Laplace transform to find y(0.6).
Answer key
- 1. f′(0⁺) = 26
- 2. f(∞) = 0.4167
- 3. f(0.1) = 0.1863
- 4. f(0.1) = 4.156
- 5. g(0.4) = 0.6774
- 6. y(0.6) = 2.573
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