A 100 lb weight is attached to a vertical spring, which stretches the spring 1 ft. Then the weight is subjected to a periodic external force f(t) = f0 cos !t. For what value of the circular frequency ! will resonance occur?

Calculate the first and second velocities of the car with four washers attached to the pulley, using the formulas v1 = 0.25 m / t1 , and v2 = 0.25 m / (t2 – t1) where t1 and t2 are the average times the car took to reach the 0.25 and the 0.50 meter marks. record these velocities, to two decimal places, in table e.