Find the inverse Laplace transform f(t) of F(s) = 14s/(s² + 36) with a table of transform pairs, and evaluate f(0.2).
Laplace transforms worksheet with answers
1.Easy
F(s) = 14s/(s² + 36)t = 0.2 s
f(0.2) =
2.Easy
A signal f(t) has the Laplace transform F(s) = (8s + 9)/(s² + 6s + 14). Find the initial slope f′(0⁺) with the initial value theorem.
F(s) = (8s + 9)/(s² + 6s + 14)
f′(0⁺) =
3.Medium
Find f(t) for F(s) = 55/(s(s + 2)(s + 5)) by partial fractions, and evaluate f(0.2).
F(s) = 55/(s(s + 2)(s + 5))t = 0.2 s
f(0.2) =
4.Medium
Find f(t) for F(s) = (6s + 24)/(s² + 4s + 4) and evaluate f(0.25).
F(s) = (6s + 24)/(s² + 4s + 4)t = 0.25 s
f(0.25) =
5.Hard
A system obeys y″ + 10y′ + 24y = 72·u(t), with y(0) = 3 and y′(0) = 0. At t = 0 a step input u(t) = 10 is applied. Use the Laplace transform to find y(0.2).
y″ + 10y′ + 24y = 72·u(t)y(0) = 3y′(0) = 0u(t) = 10t = 0.2 s
y(0.2) =
6.Hard
A system obeys y″ + 5y′ + 6y = 6·u(t), with y(0) = 5 and y′(0) = 0. At t = 0 a step input u(t) = 2 is applied. Use the Laplace transform to find y(0.1).
y″ + 5y′ + 6y = 6·u(t)y(0) = 5y′(0) = 0u(t) = 2t = 0.1 s
y(0.1) =
Answer key
- 1. f(0.2) = 5.073
- 2. f′(0⁺) = −39
- 3. f(0.2) = 0.7043
- 4. f(0.25) = 5.459
- 5. y(0.2) = 9.869
- 6. y(0.1) = 4.924
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