If an Undamped springmass system with weight 16 lb and sprin

If an Undamped spring-mass system with weight 16 lb and spring constant 1/3 lb/in is suddenly set in motion at time t = 0 by an external force 4 cos 2square root 2t lb, determine the subsequent motion. Will pure resonance occur?

Solution

k = 1/3 lb/in = 58.37 N/m

m = 16 lb = 71.17 N

w = root(k/m) = root ( 58.37/71.17) = 0.9056

here force frequency = 2 * sqrt(2)

is not matching with the natural frequency.

Hence, resonance will not be there.