A first-order system G(s) = 5/(10s + 1) receives a step input of size 1 at t = 0, starting from rest. How long does the output take to reach 99 % of its final value? Find t.
Step response worksheet with answers
An uncharged capacitor C = 10 µF is charged from a 10 V step source through a resistor R = 10 kΩ. How long after closing the switch does the capacitor voltage reach 75 % of its final value? Find t in ms.
A system has the transfer function G(s) = 33/(s² + 2s + 33) and receives a unit step input. The poles are s = σ ± jωd. Find the real part σ.
A system has the transfer function G(s) = 297/(s² + 8s + 99) and receives a unit step input. Find the natural frequency ωn in rad/s.
A mass m = 10 kg hangs on a spring k = 5000 N/m with a viscous damper c = 45 N·s/m (m·x″ + c·x′ + k·x = F). At rest in equilibrium, a constant force F = 100 N is suddenly applied. Find the largest displacement xmax in mm.
A unity negative feedback loop has G(s) = 225/(s(s + 10)). Find the 2 % settling time ts of the closed-loop step response, using ts ≈ 4/(ζωₙ).
Answer key
- 1. t = 46.05 s
- 2. t = 138.6 ms
- 3. σ = −1
- 4. ωn = 9.95 rad/s
- 5. xmax = 34.56 mm
- 6. ts = 0.8 s
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