An uncharged capacitor C = 4.7 µF is charged from a 12 V step source through a resistor R = 2.2 kΩ. Find the 10–90 % rise time tr of the capacitor voltage, in ms.
Step response worksheet with answers
A first-order system G(s) = 2/(s + 1) receives a step input of size 20 at t = 0, starting from rest. How long does the output take to reach 75 % of its final value? Find t.
A system has the transfer function G(s) = 64/(s² + 7s + 32) and receives a unit step input. Find the 2 % settling time ts of the step response, using ts ≈ 4/(ζωₙ).
A system has the transfer function G(s) = 20/(s² + 9s + 40) and receives a unit step input. Find the peak time tp of the step response.
A mass m = 4 kg hangs on a spring k = 800 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 = 25 N is suddenly applied. Find the percent overshoot %OS of the displacement.
A mass m = 4 kg hangs on a spring k = 400 N/m with a viscous damper c = 32 N·s/m (m·x″ + c·x′ + k·x = F). At rest in equilibrium, a constant force F = 5 N is suddenly applied. Find the damping ratio ζ.
Answer key
- 1. tr = 22.72 ms
- 2. t = 1.386 s
- 3. ts = 1.143 s
- 4. tp = 0.7069 s
- 5. %OS = 25.62 %
- 6. ζ = 0.4
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