A signal f(t) has the Laplace transform F(s) = (8s + 19)/(s² + 4s + 24). 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) = (−2s + 35)/(s² + 3s + 5). Find the initial slope f′(0⁺) with the initial value theorem.
Find f(t) for F(s) = 60/(s(s + 4)(s + 5)) by partial fractions, and evaluate f(0.1).
F(s) = (4s + 35)/(s² + 15s + 56). Its inverse transform has the form f(t) = A·e−7t + B·e−8t. Find the coefficient A by partial fractions.
A system is described by the differential equation y″ + 2y′ + 17y = u′ + 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 = 1.2 s. Find g(1.2).
A system obeys y″ + 8y′ + 12y = 12·u(t). It starts at rest (y(0) = 0, y′(0) = 0) and the input is a step u(t) = 1 for t ≥ 0. Use the Laplace transform to find the output y(0.25).
Answer key
- 1. f′(0⁺) = −13
- 2. f′(0⁺) = 41
- 3. f(0.1) = 0.2236
- 4. A = 7
- 5. g(1.2) = −0.1987
- 6. y(0.25) = 0.2018
Full step-by-step solutions: practise this topic on examproblems.com.