A 480-gg block on a frictionless surface is attached to a rather limp spring of constant k=8.7N/mk=8.7N/m. A second block rests on the first, and the whole system executes simple harmonic motion with a period of 1.2 ss . When the amplitude of the motion is increased to 35 cmcm, the upper block just begins to slip. What is the coefficient of static friction between the blocks?

A spring is hung from the ceiling. A 0.312-kg block is then attached to the free end of the spring. When released from rest, the block drops 0.123 m before momentarily coming to rest, after which it moves back upward. (a) What is the spring constant of the spring? (b) Find the angular frequency of the block's vibrations.

The wheel is attached to the spring. The mass of the wheel is m=20 kg. The radius of the wheel is 0.6m. The radius of gyration kG=0.4 m. The spring’s unstretched length is L0=1.0 m. The stiffness coefficient of the spring is k=2.0 N/m. The wheel is released from rest at the state 1 when the angle between the spring and the vertical direction is θ=30°. The wheel rolls without slipping and passes the position at the state 2 when the angle is θ=0°. The spring’s length at the state 2 is L2=4 m. (11) The angular velocity at the state 2?_______(rad/s) (two decimal places)

券 A child bounces in a harness suspended from a door frame by three elastic bands. (a) If each elastic band stretches 0.200 m while supporting a 5.95-kg child, what is the force constant for each elastic band? N/m (b) What is the time for one complete bounce of this child? (c) What is the child's maximum velocity if the amplitude of her bounce is 0.200 m? m/s