A mass–spring–damper is described by y″ + 1.5y′ + 9y = 0. Compare it with y″ + 2ζωny′ + ωn²y = 0 and find the damping ratio ζ.
Differential equations worksheet with answers
1.Easy
y″ + 1.5y′ + 9y = 0
ζ =
2.Easy
A mass–spring–damper is described by y″ + 12y′ + 100y = 0. Compare it with y″ + 2ζωny′ + ωn²y = 0 and find the damping ratio ζ.
y″ + 12y′ + 100y = 0
ζ =
3.Medium
Solve y″ + 2y′ + y = 0 with y(0) = 3 and y′(0) = -1. Find y(1.5).
y″ + 2y′ + y = 0y(0) = 3y′(0) = -1
y(1.5) =
4.Medium
Solve y″ + 8y′ + 15y = 0 with y(0) = 3 and y′(0) = -2. Find y(0.5).
y″ + 8y′ + 15y = 0y(0) = 3y′(0) = -2
y(0.5) =
5.Hard
A system obeys y″ + y′ + 9.25y = 18.5 for t ≥ 0, starting from rest: y(0) = 0, y′(0) = 0. Find y(0.25); angles in radians.
y″ + y′ + 9.25y = 18.5y(0) = 0y′(0) = 0
y(0.25) =
6.Hard
Solve y″ + 3y′ + 6.25y = 0 with y(0) = 1 and y′(0) = 0 (released from rest). Find y(1.5); angles in radians.
y″ + 3y′ + 6.25y = 0y(0) = 1y′(0) = 0
y(1.5) =
Answer key
- 1. ζ = 0.25
- 2. ζ = 0.6
- 3. y(1.5) = 1.339
- 4. y(0.5) = 1.163
- 5. y(0.25) = 0.5081
- 6. y(1.5) = −0.09319
Full step-by-step solutions: practise this topic on examproblems.com.